NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado i

NIST Special Publication 1164

Preliminary Reconnaissance of the

May 20, 2013, Newcastle-Moore

Tornado in Oklahoma

Erica D. Kuligowski

Long T. Phan

Marc L. Levitan

Engineering Laboratory

National Institute of Standards and Technology

David P. Jorgensen

Warning R&D Division

National Severe Storms Laboratory

National Oceanic and Atmospheric Administration

December 2013

U.S. Department of Commerce Penny Pritzker, Secretary

National Institute of Standards and Technology

Patrick D. Gallagher, Under Secretary of Commerce

for Standards and Technology and Director

Disclaimer No. 1

Certain commercial entities, equipment, or materials may be identified in this document in order to describe an

experimental procedure or concept adequately. Such identification is not intended to imply recommendation or

endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities,

materials, or equipment are necessarily the best available for the purpose. Disclaimer No. 2

NIST takes no position as to whether the design or construction of any building discussed in this report was

compliant with any code. Disclaimer No. 3

The policy of NIST is to use the International System of Units in all publications. In this document, however, units

are presented in the system prevalent in the relevant discipline, although in some cases more than one system of

units may be presented. Use in Legal Proceedings

No part of any report resulting from a NIST investigation into a structural failure or from an investigation under the

National Construction Safety Team Act may be used in any suit or action for damages arising out of any matter

mentioned in such report (15 U.S.C. 281a, as amended). Copyright This NIST publication is a work of the United States Government not subject to copyright protection within the

United States under Title 17 United States Code § 105. This publication may include copyrighted content (such as

photographs) used with permission of the credited copyright holder. Reproduction, redistribution or reuse of such

copyrighted content apart from this publication may require permission, which should be sought from the credited

copyright holder. Where no copyright holder or source is credited for a figure or table in this publication, the source

is NIST, which would appreciate attribution.

National Institute of Standards and Technology Special Publication 1164

Natl. Inst. Stand. Technol. Spec. Publ. 1164, 81 pages (December 2013)

CODEN: NSPUE2

Cover images (clockwise from top left): remains of a classroom at Briarwood Elementary School (source NIST); debris field

(source FEMA/Andrea Booher); aerial view of tornado path (source NOAA/Jim Ladue); tokens of hope at Plaza Towers

Elementary School (source FEMA/Dominick Biocchi); steel dumpster that damaged roof of Moore Medical Center (source

NIST).

Acknowledgements

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado iii

ACKNOWLEDGEMENTS

The National Institute of Standards and Technology (NIST) would like to gratefully

acknowledge the assistance of all who provided data and information in support of this

preliminary reconnaissance. NIST has received considerable cooperation and information from

Federal, State, and local authorities and the private sector. Local authorities providing

information include Moore Emergency Management, Moore Community Development

Department, Moore Fire Department, Moore Police Department, Moore Public School District,

Oklahoma City Clerk, Oklahoma City Fire Department, and mutual aid first responders from the

Tulsa Fire Department and the Weatherford Fire Department. State authorities providing

information include the Oklahoma Department of Insurance. Federal authorities providing

information include the National Oceanic and Atmospheric Administration, the National Severe

Storms Laboratory and the National Weather Service Norman Forecast Office. Private sector

organizations providing information include the Norman Regional Health System, JHBR

Architecture, and Bearing Tree Land Surveying.

NIST also gratefully acknowledges the assistance of teachers and staff of Plaza Towers and

Briarwood Elementary Schools, staff of the Moore Medical Center, and first responders, who

provided information through interviews.

We would additionally like to acknowledge the technical assistance provided during the field

deployment by Charlie Carter of the American Institute of Steel Construction, and technical and

institutional support provided by our NIST colleagues who worked diligently to make the

preliminary reconnaissance successful. These include Howard Harary, Eric Letvin, Jason

Averill, Steve Cauffman, Rena Elkin, Fahim Sadek, Frank Lombardo, Sonum Chaudhari, Kirk

Dohne, Andrew Mundy, Carolyn Rowland, S. Shyam Sunder, Kellie Beall, Rose Van Camp, and

Bessmarie Young from the NIST’s Engineering Laboratory; Michael Newman from the NIST’s

Public and Business Affairs Office; and Henry Wixon from the NIST Director’s Office.

Acknowledgements

iv NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

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Tables of Contents

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado v

TABLE OF CONTENTS

Acknowledgements ........................................................................................................................ iii

Table of Contents .............................................................................................................................v

List of Figures ............................................................................................................................... vii

List of Tables ................................................................................................................................. xi

List of Acronyms, Abbreviations, and Conversion Factors .......................................................... xii

Abstract ......................................................................................................................................... xv

Executive Summary .................................................................................................................... xvii

E.1 Introduction .................................................................................................................. xvii

E.2 NIST Response and Scope of the Preliminary Reconnaissance .................................. xvii

E.3 Hazard Context ........................................................................................................... xviii

E.4 Observations of the Preliminary Reconnaissance ....................................................... xviii

Chapter 1. Introduction .................................................................................................................. 1

1.1 Event Overview ............................................................................................................... 1

1.2 Overview of Damage and Impacts ................................................................................... 2

1.3 Overview and Scope of NIST Preliminary Reconnaissance ............................................ 2

1.4 Organization of Report .................................................................................................... 4

Chapter 2. The Tornado ................................................................................................................. 5

2.1 Moore Tornado History and Preparedness ...................................................................... 5

2.2 Meteorological Description ............................................................................................. 6

2.3 Estimated Wind Speeds and Observed Damage ............................................................ 10

Chapter 3. Emergency Communications in Moore, Oklahoma ................................................... 17

3.1 Emergency Communications System ............................................................................ 17

3.2 Emergency Communications on May 20, 2013 ............................................................. 19

Chapter 4. Building Performance, Emergency Operations, and Life Safety Outcomes .............. 25

4.1 Introduction .................................................................................................................... 25

Tables of Contents

vi NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

4.2 Plaza Towers Elementary School .................................................................................. 26

4.3 Briarwood Elementary School ....................................................................................... 34

4.4 Moore Medical Center ................................................................................................... 42

Chapter 5. Observations ............................................................................................................... 51

References ..................................................................................................................................... 55

Appendix. Tornado Emergency Procedures for Surveyed Facilities ........................................... 57

List of Figures

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado vii

LIST OF FIGURES

Figure 2-1. NOAA/NWS/SPC Convective outlook for Monday, May 20, 2013 issued at 1:17

AM CDT May 20, 2013, showing highest risk for EF-2 – EF-5 tornadoes to be

central Oklahoma. The black dot indicates the approximate location of Moore,

OK. .......................................................................................................................... 8

Figure 2-2. Storm-based tornado warning polygon (red lines) issued at 2:40 PM CDT

Monday, May 20, 2013 (top) and tornado emergency polygon issued at 3:01 PM

CDT (bottom). Background colors are radar reflectivity from the KTLX radar. ... 9

Figure 2-3. Estimated centerline of tornado damage path (in red) and locations of three critical

and educational facilities surveyed. Tornado locations and times estimated from

NWS radar data are also shown.(red dots; every 5 minutes) ................................ 10

Figure 2-4. Tornado damage path map showing point estimates of EF damage at specific

locations (triangles) and swaths for EF-0 (turquoise), EF-1 (green), EF-2 (yellow),

EF-3 (brown), EF-4 (red) and EF-5 (purple) intensity damage (data source

NOAA/NWS). The locations where damage was evaluated represents only a

small percentage of the number of buildings damaged or destroyed by the

tornado. ................................................................................................................. 12

Figure 2-5. Two spans of the historic trestle bridge on US 62 running parallel to I-44 were

destroyed. The bridge had been closed to traffic since 1963 but carried water

pipes across the Canadian River. .......................................................................... 13

Figure 2-6. Aerial view (facing east) of damage to the Moore Medical Center (upper left),

with heavily damaged residential neighborhood immediately west of the medical

center in the foreground . ...................................................................................... 14

Figure 2-7. EF rated damage by NWS west of Interstate 35 in the vicinity of Briarwood and

Plaza Tower Elementary Schools and the Moore Medical Center. The triangles

indicate locations where damage was assessed and the triangle color indicates the

EF number assigned to each assessment. The red rectangle shows the approximate

field of view of the aerial photo in Figure 2-6. ..................................................... 15

Figure 3-1. Map showing location of sirens in Moore. ............................................................18

Figure 3-2. Seven-day forecast published on Thursday, May 16, 2013, indicating ‘Significant

Severe Storms Possible’ for May 19-20. .............................................................. 20

Figure 3-3. Severe thunderstorm warning polygon issued at 2:12 pm CDT, including

Moore. ................................................................................................................... 21

Figure 3-4. Tornado warning polygon issued at 2:40 pm CDT, including Moore. ................. 22

List of Figures

viii NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 4-1. Aerial overview, after the tornado, showing NIST-surveyed facilities relative to

the estimated center of the tornado damage path (red line) ...................................26

Figure 4-2. Aerial photograph of Plaza Towers Elementary School prior to the tornado. ...... 27

Figure 4-3. Designated areas of safety for tornadoes for the Plaza Towers Elementary School.

The yellow shaded areas indicate the locations of the bathrooms used for shelter

on May 20, 2013. The area shaded in red indicated where seven children died. . 28

Figure 4-4. Aerial photograph of Plaza Towers Elementary School and proximity to estimated

center of tornado damage path. ............................................................................. 30

Figure 4-5. Post-tornado aerial view (looking northeast) of the Plaza Towers Elementary

School taken May 21, 2013. Much of the debris was already moved by the time

of this photograph as part of the search and rescue operations............................. 30

Figure 4-6. Damage to the hallway and classrooms of the new main classroom building

(complete loss of roof and many walls) where the 7 fatalities occurred (most of

the debris has already been removed). Note: this hallway area was a designated

area of safety. ........................................................................................................ 32

Figure 4-7. Collapsed southwest wing of original main classroom building. ......................... 32

Figure 4-8. Damaged interior of a classroom in the original main classroom building. ......... 33

Figure 4-9. Collapsed Gymnasium building (Note the interior Gym Office surrounded by a

CMU wall remained standing). ............................................................................. 33

Figure 4-10. Aerial overview of the Briarwood Elementary School before the tornado. .......... 34

Figure 4-11. Tornado safety areas for Briarwood Elementary School. The students and staff

generally sheltered according to the tornado plan (gray shaded areas), except the

use of the bathrooms in the 400 building (yellow shaded area). .......................... 35

Figure 4-12. Bathrooms used for shelter in the 400 building. ................................................... 37

Figure 4- 13. Aerial photograph of Briarwood Elementary School and proximity to estimated

center of tornado damage path (red line). ............................................................. 37

Figure 4-14. Collapsed Multipurpose Building ......................................................................... 39

Figure 4-15. Building 300 (fuel storage tank on top) ................................................................ 39

Figure 4-16. Building 200 (complete demolition with only boy’s and girl’s bathrooms remain

standing) ................................................................................................................ 40

List of Figures

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado ix

Figure 4-17. Cafeteria. Complete structural failure with only the interior bathroom remained

standing. ................................................................................................................ 40

Figure 4-18. An interior view of a classroom in the 400 Building where portion of the

building’s metal roof system was lost. .................................................................. 41

Figure 4-19. Hallway of Building 400 after the tornado (designated tornado safety area and

initial location of Building 400 occupants before moving to the bathrooms just

before the tornado struck) ..................................................................................... 41

Figure 4-20. Aerial photograph of Moore Medical Center before the tornado. ........................ 43

Figure 4-21. Cafeteria located on the first floor interior of the hospital where hospital patients

sheltered during the tornado. ................................................................................. 45

Figure 4-22. Physicians were relocated from the cafeteria to the walk in freezers for anticipated

additional level of protection for staff that would be needed for response and

recovery................................................................................................................. 46

Figure 4- 23. Aerial photograph of Moore Medical Center shortly after the tornado struck

showing estimated centerline of tornado track (in red) ........................................ 46

Figure 4- 24. Aerial view of the heavily damaged Moore Medical Center (looking south-east).

Circled locations indicate areas of roof deck damage. ......................................... 47

Figure 4-25. Damage to the building envelope of Moore Medical Center ................................ 47

Figure 4-26. Damage to the envelope of Moore Medical Center (glazing) ............................... 48

Figure 4-27. Damage to the interior due wind and debris infiltration. ...................................... 48

Figure 4-28. Impact damage to roof bar joists from steel trash dumpster and loss of steel roof

decking. ................................................................................................................. 49

Figure 4-29. Examples of broken interior doors. ....................................................................... 49

List of Figures

x NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

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List of Tables

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado xi

LIST OF TABLES

Table 2-1. Enhanced Fujita Scale ........................................................................................... 11

List of Tables

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Acronyms, Abbreviations, and Conversion Factors

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado xiii

LIST OF ACRONYMS, ABBREVIATIONS, AND CONVERSION FACTORS

Acronyms

BOCA Building Officials and Code Administrators

BTS box-type system

CDT central daylight time

CMU concrete masonry unit

EF Enhanced Fujita

EOC Emergency Operations Center

FEMA Federal Emergency Management Agency

GIS geographic information system

IBC International Building Code

ICC International Code Council

IRC International Residential Code

MOB Medical Office Building

NIST National Institute of Standards and Technology

NOAA National Oceanic and Atmospheric Administration

NSF National Science Foundation

NSSL National Severe Storms Laboratory

NWS National Weather Service

OGE Oklahoma Gas and Electric

SPC Storm Prediction Center

WCM Warning Coordination Meteorologist

WFO Weather Forecast Office

Abbreviations and Conversion Factors

ft foot, feet

km kilometer(s)

m meter(s), 1 m = 3.281 ft

m/s meter(s) per second, 0.447 m/s = 1 mph

mph mile(s) per hour

Acronyms, Abbreviations, and Conversion Factors

xiv NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

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Abstract

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado xv

ABSTRACT

This is a report on the National Institute of Standards and Technology (NIST) reconnaissance to

collect information on the performance of one critical facility and two educational facilities in

the May 20, 2013, Newcastle-Moore tornado in Oklahoma. The information collected includes

the physical performance of buildings and designated safe areas of the surveyed facilities (the

Moore Medical Center and Plaza Towers and Briarwood Elementary Schools), emergency

communications systems and emergency operations during and after the tornado, and life safety

outcomes. The report describes the environmental conditions, warning information transmitted

to the public, as well as emergency response operations, observed building damage, and fatalities

and injuries that occurred at each of the three surveyed facilities.

Following the EF-5 tornado that tore through Moore, Oklahoma and surrounding areas on May

20, 2013, causing substantial loss of life and widespread damage, NIST, as part of its Disaster

and Failure Studies Program, deployed a team on May 22, 2013, to conduct a Preliminary

Reconnaissance. The scope of the reconnaissance was limited, and was undertaken to support

the NIST technical investigation, then in progress, of the 2011 EF-5 tornado that devastated

Joplin, Missouri. The reconnaissance was conducted in cooperation with the National Oceanic

and Atmospheric Administration’s National Severe Storms Laboratory (NOAA’s NSSL). The

team consisted of three researchers from NIST’s Engineering Laboratory, with expertise in

structural engineering, wind engineering, and disaster sociology, and a researcher from NSSL,

with expertise in meteorology and severe storm predictions and warnings.

This report provides an account of the tornado and the warning information transmitted to the

public, a description of the pre-event emergency plans and procedures and specific actions taken

at the surveyed facilities in response to the tornado, information on the construction and physical

performance of the buildings at the facilities, and life safety outcomes (fatalities and injuries) at

each location. The report concludes with observations on the performance of the emergency

communications system during the May 20, 2013, Newcastle-Moore tornado, and for the specific

facilities studied, on the performance of emergency operations and physical performance of their

buildings and designated safe areas.

Keywords: Building performance, designated safe area, emergency communications, fatalities,

emergency response, injuries, tornado, tornado shelter, warning.

Abstract

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Executive Summary

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado xvii

EXECUTIVE SUMMARY

E.1 Introduction

This report documents observations of the National Institute of Standards and Technology

(NIST) Preliminary Reconnaissance of the May 20, 2013, Newcastle-Moore tornado, to collect

information on the performance of one critical facility and two educational facilities. The

information collected includes the physical performance of buildings and designated safe areas

of the three facilities, emergency communications systems and emergency operations during and

after the tornado, and life safety outcomes. The reconnaissance was conducted in cooperation

with the National Oceanic and Atmospheric Administration’s National Severe Storms

Laboratory (NOAA’s NSSL).

This work complements an ongoing NIST technical investigation of the May 22, 2011, tornado

in Joplin, Missouri, which killed 161 people and damaged or destroyed approximately 8,000

buildings. Disasters such as those in Moore and Joplin, while tragic, do provide an important

opportunity to learn from the performance of emergency communications systems and buildings

and infrastructure during catastrophic events. Lessons derived from such disasters can lead to

improvements in standards, codes, and practices that will reduce fatalities, injuries, and property

losses in future events.

E.2 NIST Response and Scope of the Preliminary Reconnaissance

At the time of the May 20, 2013, Newcastle-Moore tornado, NIST was nearing completion of its

technical investigation1 of the EF-5 tornado that struck Joplin, MO on May 22, 2011. The

decision was made by NIST to conduct a Preliminary Reconnaissance of the May 20, 2013,

Newcastle-Moore tornado, to identify any information that might be relevant to certain aspects of

the Joplin tornado investigation. The objectives of the Newcastle-Moore Tornado Preliminary

Reconnaissance were therefore limited to:

1. Collect data and information on the performance of the emergency communications

systems immediately prior to and during the tornado; and

2. Collect data and information on the response of critical and educational facilities

(specifically, the Moore Medical Center and Briarwood and Plaza Towers Elementary

Schools) to the tornado, including emergency operations, the physical performance of the

buildings and designated safe areas, and life safety outcomes.

The Preliminary Reconnaissance was conducted in cooperation with the NOAA’s NSSL. The

reconnaissance team consisted of three researchers from NIST’s Engineering Laboratory, with

expertise including structural engineering, wind engineering, and disaster sociology, and a

researcher from NSSL, having expertise in meteorology and severe storm predictions and

warnings. All team members had experience in conducting disaster studies following tornadoes

1 See http://www.nist.gov/el/disasterstudies/weather/joplin_tornado_2011.cfm for information on the NIST technical

investigation of the Joplin tornado.

Executive Summary

xviii NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

and other hazards. The team arrived in Moore on May 22, 2013, and collected data through May

24, 2013.

E.3 Hazard Context

Early Monday afternoon, May 20, 2013, severe thunderstorms began to develop in the area

southwest of Oklahoma City. These storms were part of a larger outbreak of severe weather that

affected the central United States on May 18-20, including 77 tornadoes across the Midwest. At

2:56 pm CDT, a tornado touched down in the rural northwest area of the City of Newcastle,

Oklahoma. It rapidly increased in size and intensity after crossing the Canadian River and

moved through rural southwest Oklahoma City. The tornado had grown to EF-5 intensity on the

Enhanced Fujita Scale, with estimated 200+ mph winds based on damage indicators, by the time

it reached the more densely populated City of Moore, Oklahoma, at around 3:15 pm. The mile-

wide tornado then moved to the east northeast across Moore at a little more than 20 mph,

destroying neighborhoods, schools, and the only hospital in this city of 57,810 people. The

tornado finally dissipated about 4.8 miles east of Moore, at around 3:35 pm, for a total path

length of 14 miles and approximately 39 minutes on the ground.

The May 20, 2013, Newcastle-Moore tornado caused 24 fatalities, including seven children who

died when the elementary school classroom building in which they took shelter collapsed. Three

hundred eighty-seven people were treated for injuries at local hospitals. Fatalities occurred

despite (1) early identification of potential severe weather in Moore several days in advance; (2)

longer warning time than the national average warning lead time (~16 minutes versus ~14

minutes2); and, (3) for the seven fatalities at the Plaza Towers Elementary School, sheltering

action taken at the designated safe area within the school.

An estimated 2,393 structures were impacted by the tornado, including 1,128 structures that were

destroyed and 335 that sustained major damage. Residential buildings took the brunt of the

storm’s damage, with non-residential buildings accounting for 85 of the damaged structures.

E.4 Observations of the Preliminary Reconnaissance

Observations based on data and information collected during the course of this Preliminary

Reconnaissance are presented below. They are arranged in five groups, the first three providing

context, and the last two addressing the specific objectives of the Preliminary Reconnaissance.

Tornado History and Preparedness

The City of Moore (and surrounding areas) have had much experience in recent years

with tornado disasters, including strikes by one F-2, two F-4/EF-4, and two F-5/EF-5

tornadoes since 1998 (a Fujita Scale F-2 tornado in 1998, an F-5 tornado in1999, an F-4

2 NWS average for 2008 (www.nws.noaa.gov/cfo/program_planning/doc/FY-

2009%20NOAA's%20NWS%20National%20Performance%20Measures%20-%20Graph%20Update.pdf).

Executive Summary

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado xix

tornado in 2003, an Enhanced Fujita Scale3 EF-4 tornado in 2010, and the May 20, 2013,

Newcastle-Moore EF-5 tornado). Moore is one of just a few communities nationwide to

have ever been struck by two F-5/EF-5 tornadoes.

Moore’s work to prepare for tornadoes has included implementing storm monitoring and

education and training programs, becoming a NWS certified StormReady Community in

2001, and maintaining that certification since. It was most recently recertified in 2012.

Elements of the program include maintaining a 24-hour emergency operations center;

having multiple methods to receive severe weather warnings and forecasts and to alert the

public; promoting the importance of public readiness through community seminars; and

maintaining a formal hazardous weather plan, which includes training severe weather

spotters and holding emergency exercises.

While some research has shown that high false alarm rates can contribute to complacency

by the public in response to warnings, the false alarm rate for official tornado warnings in

Moore in recent years was considerably lower than the national average. During the era

of storm-based warning polygons (as opposed to earlier county-wide warnings), between

October 2007 and May 19, 2013, 16 official tornado warnings were issued for all or some

parts of Moore, 12 of which were followed by verified tornadoes. This yielded a false

alarm rate for the Moore area of 25 percent (4 false alarms out of 16 warnings), compared

to the national average false alarm rate of 74 percent for 2010.

Building Codes and Storm Shelters

Moore had adopted national model codes governing design and construction of buildings,

and was enforcing the 2009 International Code Council (ICC) International Building

Code (IBC) and the 2009 ICC International Residential Code for One- and Two-Family

Dwelling (IRC) at the time of the Newcastle-Moore tornado.

Tornadoes are not explicitly considered in either the 2009 IBC or 2009 IRC for any types

of buildings, except storm shelters. Although design wind speeds required by those

codes are in the range of EF-1 tornadoes, the codes do not address potentially greater

lateral and roof uplift pressures in tornadoes compared to other types of windstorms, and

do not address windborne debris, which is a significant contributor to building damage in

tornadoes.

There were no public or community shelters in Moore at the time of the Newcastle-

Moore tornado. The City’s strategy was to recommend shelter-in-place, except for

occupants in mobile homes or portable buildings, who were advised go to a substantial

structure. The City’s stated rationale was twofold: there were no public buildings having

a suitable location for a shelter; and the overall risk was less to shelter-in-place in a

reasonably well-constructed residence (considering available warning time, travel time to

a shelter, traffic, and other factors).

3 The National Weather Service (NWS) switched from rating tornado intensity using the Fujita Scale to the

Enhanced Fujita Scale in 2007 (see Section 2.3 for more information).

Executive Summary

xx NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Over 3,000 residential shelters have been constructed in Moore and were registered with

the city at the time of the Newcastle-Moore tornado, perhaps the highest number of

residential shelters per capita in the U.S.

Installation of storm shelters in homes or other buildings is strictly voluntary; neither the

national model building codes adopted by Moore nor local amendments require storm

shelters.

Events Immediately Prior to the Tornado

The threat of severe weather for the Moore area on May 20, 2013, was identified as early

as May 15 by the NWS Storm Prediction Center (SPC). The Hazardous Weather

Outlook on May 15 indicated the possibility of severe storms on May 19-20, which was

expanded to include possible destructive hail and tornadoes in the May 16 Outlook. The

Convective Outlook issued at 1:00 am CDT on May 20 indicated a 10% or greater

probability of EF2-EF5 tornadoes occurring within 25 miles of a point for the central

Oklahoma region on the afternoon of May 20.

The tornado touched down while Moore schools were still in session. However, many

parents had picked up their children earlier in the day in response to increasing concerns

about the weather, significantly reducing the number of students at the schools when the

tornado struck. Due to the threat of severe weather that afternoon, Moore Public Schools

made the decision by 9:00 am CDT to cancel all afterschool activities on May 20. By

1:30 pm, the decision was made to shelter-in-place (i.e., not run the buses or release the

students at the normal 3:00 pm dismissal time).

Observations on Objective 1: Performance of the emergency communications systems

immediately prior to and during the tornado

The NWS Weather Forecast Office (WFO) in Norman made extensive use of

nontraditional communications on May 20 to provide more frequently updated

information about the possibility of severe weather and about the tornado warnings.

These new communication methods included recorded severe weather briefings on

YouTube, direct emails to stakeholders (e.g., emergency managers, school

administrators), and Twitter and Facebook posts.

The first official tornado warning for the Moore area was issued at 2:40 pm CDT, and the

tornado touched down at 2:56 pm, for a lead time of 16 minutes. The 2010 national

average tornado warning lead time is 14 minutes (latest available data). The leading edge

of the tornado reached Briarwood Elementary School at approximately 3:15 pm, Plaza

Towers Elementary School a few minutes later, and the Moore Medical Center at

approximately 3:20 pm.

Executive Summary

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado xxi

An official Tornado Emergency warning, the most urgent official warning type, was

issued by NWS at 3:01 pm CDT. This terminology, reserved by NWS for “exceedingly

rare situations,” had only been used twice previously by the Norman WFO, for the 1999

F5 and the 2003 F4 tornadoes, both of which struck Moore and surrounding areas.

The tornado sirens in Moore were sounded six times. The initial siren was sounded

shortly following the first NWS tornado warning at 2:40 pm CDT, and the last at

approximately 3:20 pm. The sirens in Moore are only meant to alert/warn those located

outdoors and are used to indicate the urgent need to take shelter. Moore’s outdoor

warning system is also capable of transmitting pre-recorded messages from its sirens.

This feature was used only once, for the 3:11 pm activation, informing the Moore

community that the tornado warning was still in effect.

Observations on Objective 2: Response of critical and educational facilities (specifically, the

Moore Medical Center and Briarwood and Plaza Towers Elementary Schools) to the tornado,

including emergency operations, the physical performance of the buildings and designated

safe areas, and life safety outcomes.

At both Briarwood and Plaza Towers Elementary Schools, most designated tornado safe

areas were severely damaged or destroyed. Some of the designated safe areas at the

Moore Medical Center had significant damage due to collapse of interior walls and

ceilings on the second floor and due to infiltration of windborne debris in hallways on the

first floor. None of these buildings had facilities specifically designed for use as storm

shelters4 or safe rooms,

5 and none had basements.

The designated safe areas in the new main classroom building at Plaza Towers

Elementary School did not provide life safety. Seven schoolchildren died when part of

the building’s designated safe area, in which they were located, collapsed. Two adults

and one student were also significantly injured in the new main classroom building. No

fatalities occurred in the original main classroom building at Plaza Towers Elementary

School; however, two teachers and one child suffered significant injuries.

Extensive damage to the building envelope of the Moore Medical Center allowed wind,

debris, and water inside the building, causing severe damage to the interior and rendering

the hospital and medical office buildings completely nonfunctional. Damage to the

structural systems (pre-cast concrete and steel framing) was negligible.

There were no reported fatalities at Briarwood Elementary School or Moore Medical

Center. Two teacher’s assistants suffered significant injuries at Briarwood Elementary

School (in the 100 Building) and no significant injuries were reported at Moore Medical

Center.

4 As defined by the ICC 500 Standard for the Design and Construction of Storm Shelters (ICC, 2008).

5 As defined by FEMA 361, Design and Construction Guidance for Community Safe Rooms (FEMA, 2012)

Executive Summary

xxii NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

For the most part, designated safe areas as identified in emergency plans were used at the

three facilities surveyed by NIST. In some cases, last-minute decisions were made to use

smaller interior spaces or rooms, which were not previously identified in the building’s

emergency plans as designated safe areas, such as bathrooms and closets in the two

elementary schools and a walk-in freezer in the Moore Medical Center.

Smaller interior spaces (e.g., bathrooms) surrounded by reinforced masonry (CMU) walls

at both schools performed better when compared with adjacent hallways and classrooms.

The CMU walls that surrounded these interior spaces were found to more often remain

standing and thereby provide some protection against wind-borne debris.

Multiple buildings at both elementary schools suffered complete collapse or severe

damage. The elementary school buildings with box-type construction typically sustained

loss of the roof system and diaphragm, leading to partial or total collapse of the

supporting walls. Pre-engineered metal gymnasium and multipurpose buildings sustained

total structural failure.

Chapter 1

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 1

CHAPTER 1. INTRODUCTION

1.1 Event Overview

The possibility of severe weather on Monday, May 20, 2013, in the area of Moore, Oklahoma

was identified by the NWS as early as May 15, 2013, as part of an outbreak of severe weather

that did occur across the central United States on May 18-20, 2013. At 1:00 am CDT on May

20, the NWS/Storm Prediction Center (SPC) issued a probabilistic tornado outlook indicating a

10% or greater probability of Enhanced Fujita Scale EF2-EF5 tornadoes occurring within 25

miles of a point for central Oklahoma, including the City of Moore. At 8:00 am CDT, the

Warning Coordination Meteorologist (WCM) at the NWS Weather Forecast Office (WFO) in

Norman, Oklahoma sent an email to his network of leaders (e.g., emergency managers and

school administrators) warning them about the possibility of severe weather later in the day, and

the potential for serious issues if tornadic storms occurred during school dismissal time. The

WCM was also sending out information by other nontraditional channels, such as recorded

briefings on YouTube and via social media (Twitter and Facebook). By 9:00 am CDT, the

decision was made by Moore Public School District to cancel all after-school activities. The

10:00 am CDT SPC Convective Outlook predicted the peak hours for severe weather, including

tornadoes, would be between 3 pm and 8 pm.

The first tornado watch including the City of Moore was issued by the WFO in Norman,

Oklahoma at 1:10 pm. A tornado warning, based on Doppler radar indications of a severe storm,

was issued at 2:40 pm CDT, which included the cities of Newcastle and Moore, and parts of

Oklahoma City. The City of Moore sounded its siren system moments later; the first of six times

the sirens would be activated that afternoon. A small, short-lived EF-0 tornado touched down

west of the City of Newcastle at 2:45 pm, but primarily caused damage to trees.

At 2:56 pm CDT, a second tornado touched down in the rural northwest area of the City of

Newcastle. It rapidly increased in size and intensity after crossing the Canadian River and

moved through rural southwest Oklahoma City. The NWS issued a Tornado Emergency

Warning, its most urgent warning, at 3:01 pm CDT. The tornado had grown to EF-5 intensity on

the Enhanced Fujita Scale, with estimated 200+ mph winds, by the time it reached the more

densely populated City of Moore, around 3:15 pm. The mile-wide tornado moved to the east-

northeast across Moore at a little more than 20 mph, destroying neighborhoods, schools, and the

only hospital in this city of 57,810 people. The tornado finally dissipated 4.8 miles east of Moore

around 3:35 pm, for a total path length of 14 miles and time on the ground of approximately 39

minutes.

Chapter 1

2 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

1.2 Overview of Damage and Impacts

The Oklahoma Department of Emergency Management reported a total of 24 fatalities caused by

the Newcastle-Moore tornado and 387 injuries treated at local hospitals, as of May 24, 2013.6

FEMA (2013) estimated that 2,393 structures were impacted by the Newcastle-Moore tornado,

including 1,128 structures that were destroyed, 335 that sustained major damage, 629 that

sustained minor damage, and another 301 structures were ‘generally affected.’ This damage

occurred primarily to residential buildings; non-residential buildings accounted for 4 % (85 out

of 2,393) of the damaged structures. The Oklahoma Department of Insurance reported that the

total number of tornado-related insurance claims from the May 19-20, 2013 tornado outbreak

submitted as of June 4, 2013 was 32,433, including 13,938 homeowners claims, 742 commercial

property claims, and 17,492 automobile claims (claims were not tracked by individual tornado,

but the Newcastle-Moore tornado was by far the most destructive).7

Power outages from the May 19-20, 2013 outbreak in the region peaked at 61,500 customers

without power. Oklahoma Gas and Electric (OGE) reported a maximum of 18,432 outages in

Moore, which were reduced to 4,225 by May 24, 2013. OGE reported that it expected to have all

customers capable of receiving power restored by May 26, 2013. The McClain Power Plant in

Newcastle, located just outside of the tornado damage path, was knocked offline due to damaged

transmission lines to the plant. However, OGE identified that it had sufficient capacity from

other generation assets to meet customer demand. Low water pressure was experienced during

the first two days after the tornado, but water quality was not affected.8

The Moore Medical Center, consisting of a hospital and adjoining medical office buildings, was

heavily damaged and rendered completely nonfunctional, although no lives were lost. Thirteen

patients located in the hospital when the tornado hit were transferred to other area hospitals. The

entire facility was ultimately demolished, leaving the City of Moore without a hospital. Two

elementary schools in the Moore Public School District were destroyed and several other schools

were damaged, including the district administration building. Seven students were killed in one

of the buildings that collapsed at Plaza Towers Elementary School. The school district canceled

classes through the end of the school year (which had been scheduled to end on May 23, 2013).

1.3 Overview and Scope of NIST Preliminary Reconnaissance

NIST is working to reduce the risk to buildings and communities posed by tornadoes through

improvements to building, fire, and emergency communications standards, codes, and practices

based upon findings from studies of these events. NIST has statutory authority to deploy teams

of technical experts to conduct disaster studies under the NIST Organic Act (15 U.S.C. § 271 et

seq., as amended) and the National Windstorm Impact Reduction Act of 2004 (Pub. Law 108-

360; 118 Stat. 1668). NIST conducts two types of disaster studies: a Preliminary

6 Oklahoma Department of Emergency Management

(http://www.ok.gov/OEM/Emergencies_&_Disasters/2013/20130518_Severe_Weather_Event/20130524_Situation_

Update_7.html). 7 Oklahoma Insurance Department

(http://www.ok.gov/triton/modules/newsroom/newsroom_article.php?id=157&article_id=11981). 8 City of Moore (http://www.cityofmoore.com/city-moore-assures-residents-water-safe).

Chapter 1

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 3

Reconnaissance, which is a field study at the disaster or failure site to gather information and to

help determine if a technical investigation is warranted; and a Technical Investigation, which is a

fact-finding study that may include an assessment of the safety and performance of buildings and

infrastructure, associated hazard(s), and/or emergency response and evacuation procedures and

will likely result in recommendations for improvements to standards, codes, and practices and/or

new knowledge.9

At the time of the May 20, 2013, Newcastle-Moore tornado, NIST was nearing completion of its

technical investigation10

of the EF-5 tornado that struck Joplin, Missouri on May 22, 2011. The

decision was made by NIST to conduct a Preliminary Reconnaissance of the Newcastle-Moore

tornado, to identify any information that might be relevant to certain aspects of the ongoing

Joplin tornado investigation. NIST, in cooperation with the NOAA’s National Severe Storms

Laboratory (NSSL), deployed a team to conduct a Preliminary Reconnaissance of the tornado

that struck Moore and parts of Newcastle and southern Oklahoma City, Oklahoma on May 20,

2013.

The Preliminary Reconnaissance team consisted of three researchers from NIST’s Engineering

Laboratory (EL), with expertise in disaster sociology and structural, wind, and fire protection

engineering, and a researcher from NOAA’s NSSL, with expertise in severe storm predictions

and warnings. All team members were experienced in conducting post-disaster studies following

tornadoes and other hazards. The team collected data in Moore from May 22 through May 24,

2013.

The objectives of the Preliminary Reconnaissance were to:

1. Collect data and information on the performance of the emergency communications

systems immediately prior to and during the tornado; and

2. Collect data and information on the response of critical and educational facilities

(specifically, the Moore Medical Center and Briarwood and Plaza Towers Elementary

Schools) to the tornado, including emergency operations, the physical performance of the

buildings and designated safe areas, and life safety outcomes.

The scope of the reconnaissance was limited, defined to support the nearly completed NIST

technical investigation of the Joplin tornado. Data collected during the Moore reconnaissance

support two of the five objectives of the Joplin study.

The reconnaissance team documented the physical damage to understand the physical

performance of building and designated safe areas, as well as life safety outcomes. In addition,

NIST interviewed staff at each facility to collect information on the emergency response.

Officials from the City of Moore, NWS, the Moore Public School District, and the Moore

Medical Center were also interviewed to gather information and data on emergency plans,

warnings, and emergency response. The team interviewed first responders from the City of

Moore and other communities (deployed to Moore for mutual aid) to collect information on

9 NIST (http://www.nist.gov/el/disasterstudies/about.cfm).

10 See http://www.nist.gov/el/disasterstudies/weather/joplin_tornado_2011.cfm for information on the NIST

investigation of the Joplin tornado.

Chapter 1

4 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

fatalities, injuries and rescues at the schools. Meetings were also held with NWS and NSSL to

collect meteorological information and data on tornado damage and to document warning

dissemination methodology.

NIST received considerable cooperation and information from Federal, State, and local

authorities and the private sector. Local authorities providing information include Moore

Emergency Management, Moore Community Development Department, Moore Fire

Department, Moore Police Department, Moore Public School District, Oklahoma City Clerk,

Oklahoma City Fire Department, and mutual aid first responders from the Tulsa Fire Department

and the Weatherford Fire Department. State authorities providing information include the

Oklahoma Department of Insurance. Federal authorities providing information include NOAA,

NSSL and NWS WFO in Norman, Oklahoma. Private sector organizations providing

information include the Norman Regional Health System, JHBR Architecture, and Bearing Tree

Land Surveying.

Collected data include: 1) meteorological information; 2) warning information; 3) emergency

communications procedures for the City of Moore and actions on May 20, 2013; 4) emergency

communications and response plans for the specific facilities studied, including identified refuge

locations within buildings; 5) ground and aerial photographs of buildings damaged by the

tornado; 6) building plans; and 7) interviews with emergency management officials, building

officials, first responders, school teachers and administrators, and hospital officials.

1.4 Organization of Report

This report presents information and observations from the NIST Preliminary Reconnaissance of

the May 20, 2013, Newcastle-Moore tornado. Chapter 2 provides a description of the tornado

and wind field. Chapter 3 presents information on the City of Moore’s emergency

communications systems and procedures, and warning information transmitted to the public by

NWS and the City of Moore in the time leading up to and during the tornado. For the surveyed

facilities, Chapter 4 first describes each facility and its pre-event emergency plans and

procedures, and then recounts the specific actions taken by building occupants in response to the

tornado, the damage caused by the tornado, and life safety outcomes. Chapter 5 presents

observations on the performance of the emergency communications system during the

Newcastle-Moore tornado, and observations on the emergency operations, the physical

performance of buildings and their designated safe areas, and life safety outcomes at the three

surveyed facilities.

Chapter 2

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 5

CHAPTER 2. THE TORNADO

2.1 Moore Tornado History and Preparedness

The City of Moore (population 57,810) has experienced several strong tornadoes in the last 15

years that traversed similar tracks through the central parts of the city. On October 4, 1998, an

F-2 tornado11

briefly touched down in central Moore, traversing 3 miles.12

That tornado was part

of the largest autumnal outbreak of tornadoes ever recorded in Oklahoma. On May 3, 1999, a

long-track tornado touched down at 6:23 pm in the Bridge Creek, Oklahoma area.13

That tornado

quickly strengthened into an F-4 storm, and gradually reached F-5 intensity after traveling 6.5

miles. Throughout its one hour and 25 minutes on the ground, the tornado covered 38 miles and

caused $1 billion (1999 USD) in damage. The 1999 tornado was responsible for 36 fatalities and

583 injuries.

Another strong tornado (F-4) touched down at 5:00 pm on May 8, 2003, on the west side of

Moore. This storm was part of a large-scale outbreak that included 401 tornado reports in 19

states and 1 Canadian province. More severe weather broke out that week than any other week

in U.S. history. In Moore, the May 8 storm crossed Interstate 35 and continued east to near

Tinker Air Force Base, and also affected the cities of Midwest City and Choctaw,

Oklahoma.14

That tornado caused $160 million worth of damage (2003 USD), 89 injuries, but

no fatalities. On May 10, 2010, an EF-4 tornado crossed the southern part of Moore, killing 2

and injuring 49 along its 24-mile path from north Norman, Oklahoma to Harrah, Oklahoma.15

While research has shown that high false alarm rates can contribute to complacency by the

public in response to warnings (Simmons and Sutter 2011), the false alarm rate for official

tornado warnings in Moore in recent years was considerably lower than the national average.

During the era of storm-based warning polygons (as opposed to earlier county-wide warnings),

between October 2007 and May 19, 2013, 16 official tornado warnings were issued for all or

some parts of Moore. Twelve of the 16 official tornado warnings were followed by verified

tornadoes. This yielded a false alarm rate for the Moore area of 25 percent (4 false alarms out of

16 warnings), compared to the national average false alarm rate of 74 percent for 2010.

Following the 1999 F-5 tornado, the State of Oklahoma and the Federal Emergency Management

Agency (FEMA) developed an incentive program to assist homeowners with construction of

storm shelters in houses that were being built or rebuilt after the tornado, using recently

published FEMA design guidance.16

Over 3,000 residential shelters have been constructed in

Moore and were registered with the City at the time of the tornado, perhaps the highest number

11

The NWS used the Fujita Scale (F Scale) to rate tornado intensity until 2007, when the Enhanced Fujita Scale (EF

Scale) was adopted. See section 2.3 of this report for more information. 12

NWS (http://www.srh.noaa.gov/oun/?n=events-19981004). 13

NWS (http://www.srh.noaa.gov/oun/?n=events-19990503). 14

NWS (http://www.srh.noaa.gov/oun/?n=events-20030508). 15

NWS (http://www.srh.noaa.gov/oun/?n=tornadodata-city-moore). 16

National Storm Shelter Association (http://aln.coe.ttu.edu/nssa-new/Origins.php).

Chapter 2

6 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

of residential shelters per capita in the U.S.17

In contrast, the City of Moore has no public or

community tornado shelters; its strategy is to recommend shelter-in-place, except for occupants

in mobile homes,18

who are advised go to a substantial structure.19

The City’s stated rationale is

twofold: there is no public building in Moore which has a suitable location for a shelter; and

there is less overall risk to shelter-in-place in a reasonably well-constructed residence

(considering available warning time, travel time to a shelter, traffic, and other factors).

As part of its public preparedness information, the City of Moore has a list of frequently asked

questions and answers concerning sheltering from storms on its webpage. An individual is

advised to seek shelter where he/she is already located, as close to or as far below ground level

as possible. Also, Moore recommends that individuals go to the center of the building away from

windows and to place as many barriers as possible between the outside windows and the

individual, using such items as blankets, mattresses, coats, bicycle/motorcycle helmets, etc.

Those in mobile homes or motor vehicles are advised to find the nearest building that can

provide shelter and remain there until the tornado passes.20

At the time of the Newcastle-Moore tornado, Moore had adopted the 2009 International Code

Council (ICC) International Building Code or IBC (ICC, 2009a) and the 2009 International

Residential Code for One- and Two-Family Dwelling or IRC (ICC 2009b). Installation of storm

shelters in homes or other buildings is strictly voluntary; neither the national model building

codes adopted by Moore nor local amendments require storm shelters. Tornadoes are not

explicitly considered in either the 2009 IBC or 2009 IRC for any types of buildings, except storm

shelters. Although design wind speeds required by those codes are in the range of EF-1

tornadoes, the codes do not address potentially greater lateral forces and uplift forces on the roof

in tornadoes compared to other types of windstorms (Haan et al. 2010), and do not address

windborne debris, which is a significant contributor to building damage in tornadoes (FEMA

2012).

2.2 Meteorological Description

The May 20, 2013, Newcastle-Moore tornado was part of a larger outbreak of severe weather

that affected the central United States on May 18-20, 2013. A shift in the synoptic weather

pattern over the Midwest U.S. beginning May 18 brought a strong jet stream at mid levels

superimposed on a near surface southerly flow of warm, moist air from the Gulf of Mexico.

Severe convective storms, many with embedded tornadoes, developed during the late afternoon

of May 18, producing 16 tornadoes in Kansas and Nebraska. On May 19, storms again developed

in the late afternoon producing 29 tornadoes in the Midwest U.S. (8 in Oklahoma, including a

strong EF-3 near Shawnee, Oklahoma, just east of Oklahoma City). Another outbreak of strong

storms on May 20 produced 32 tornadoes in the Midwest U.S., including 8 in Oklahoma, the

most intense of which was the Newcastle-Moore tornado.

17

Tulsa World

(http://www.tulsaworld.com/article.aspx/Moore_residents_learn_from_past_regarding_tornadoes/20130525_11_A1

_CUTLIN869479?subj=1) . 18

City of Moore (http://www.cityofmoore.com/storm-shelters). 19

City of Moore (http://www.cityofmoore.com/severe-weather-safety). 20

City of Moore (http://www.cityofmoore.com/uploaded/File/ShelteringFAQ(FINAL).pdf ).

Chapter 2

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 7

The initial indication that central Oklahoma was at risk for severe storms and possible strong

tornadoes on Monday, May 20 was NOAA/NWS/SPC’s Convective Outlook that was issued on

Wednesday May 15, at 5:00 AM CDT, based on a forecast of greater instability and wind shear

for Sunday and Monday over central and eastern Oklahoma. SPC issued a probabilistic tornado

outlook at 1:17 AM CDT on May 20 that narrowed the precise location of highest risk to central

Oklahoma (Figure 2-1). The Convective Outlook issued at 10:00 AM CDT on May 20 pinned

the timing down further, indicating peak hours for severe weather, including tornadoes, would be

between 3 pm and 8 pm.

In response to these outlooks, and further monitoring of the evolution of the large-scale

environment, particular morning soundings of convective instability and wind shear, forecasters

from NWS Norman forecast office issued a tornado watch (#191) at 1:10 PM CDT on Monday

May 20 for a large swath of central Oklahoma until 10:00 PM CDT, including Cleveland and

McClain counties that were eventually affected by the tornado. Development of convective

storms, which began around 2:00 PM CDT, was detected by the NWS Doppler radar in central

Oklahoma (called “KTLX”) along a weak cold front and dryline just west of the Oklahoma City

metro area, and extending southwest to extreme southwest Oklahoma. As those convective

storms developed further, NWS Norman forecast office issued a severe thunderstorm warning at

2:12 PM CDT. A strong circulation signature was seen in the radial velocity data (a cyclonic or

counterclockwise rotation indicative of a mesocyclone at low levels) at about 2:35 PM CDT, and

a tornado warning was issued (Figure 2-2) at 2:40 PM CDT. The warning polygon included

Moore, Newcastle, southern Oklahoma City and northern Norman.

Based on the sudden strengthening of the radar-observed mesocyclone circulation seen in the

radar radial velocity data (a “debris ball” or high reflectivity zone near the tip of the hook echo;

Figure 2-2) as well as storm spotter reports indicating a funnel cloud reaching the ground at 2:56

PM CDT, NWS Norman forecast office issued a tornado emergency warning, indicating an

extremely strong tornado hazard from this storm, at 3:01 PM CDT.

The first real-time confirmation of a tornado on the ground came at 2:56 PM CDT, just west of

the Canadian River in the rural northwest area of the City of Newcastle, from spotter reports and

observations from a television station helicopter.21

The storm crossed the Canadian River around

3:00 PM CDT, and then began to affect the more heavily populated area of Moore. The area of

western Moore (where Briarwood and Plaza Towers Elementary Schools and the Moore Medical

Center are located) was affected by the tornado starting about 3:15-3:20 PM CDT (see Figure 2-

3). The tornado’s path followed a general east-northeast direction, but veered sharply to the north

as it approached Interstate Highway 35 (I-35) and struck the Moore Medical Center. It briefly

turned east-southeast as it crossed I-35, then resumed its general east-northeast path, passing

through mostly residential neighborhoods. It then struck the Highland East Junior High School,

located a mile and a half due east of the Moore Medical Center, where it destroyed the

21

Damage survey teams sent out the next day, a joint effort by NOAA’s NWS and NSSL, documented evidence of

damage farther west than the position determined by radar at 2:56 PM. The NWS later identified this damage being

caused by a separate, short-lived EF-0 tornado, which touched down near 2:45 PM CDT about 4.4 miles west of the

small City of Newcastle, Oklahoma.

Chapter 2

8 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Source: NOAA/NWS. Enhancements by NIST.

Figure 2-1. NOAA/NWS/SPC Convective outlook for Monday May 20, 2013 issued at 1:17 AM CDT May 20, 2013, showing highest risk for EF-2 – EF-5 tornadoes to be central Oklahoma. The black dot indicates

the approximate location of Moore, OK.

gymnasium building, damaged the school building, and damaged the nearby Moore School

Board’s Administration Service Center Building. The tornado eventually dissipated 4.8 miles

east of Moore at about 3:35 PM CDT, for a total path length of about14 miles.22

The average

forward speed of the tornado during its 39 minutes on the ground was approximately 21.5 mph.

Times associated with passage of the center of the tornado at several locations along the track

were estimated using data from the NWS radar located approximately 12 miles east of Moore

(call letters KTLX) and shown in Figure 2-3. Given the size of the tornado and its forward speed,

EF-0 and greater winds would typically have begun at these locations 1 to 2 minutes prior to the

indicated time and lasted 1 to 2 minutes after the indicated time. Therefore, the duration of EF-0

or greater winds at any point along the centerline of the track would have typically been 2 to 4

minutes. The tornado was relatively close to the radar (19 miles to 6 miles as it tracked west to

22

NWS (http://www.srh.noaa.gov/oun/?n=events-20130520).

Chapter 2

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 9

Figure 2-2. Storm-based tornado warning polygon (red lines) issued at 2:40 PM CDT Monday May 20, 2013 (top) and tornado emergency polygon issued at 3:01 PM CDT (bottom). Background colors are

radar reflectivity from the KTLX radar.

© OpenStreetMap contributors. Radar data source NWS. Enhancements by NIST.

© OpenStreetMap contributors. Radar data source NWS. Enhancements by NIST.

Chapter 2

10 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 2-3. Estimated centerline of tornado damage path (in red) and locations of three critical and educational facilities surveyed. Tornado locations and times estimated from NWS radar data are also

shown (red dots; every 5 minutes).

about1500 ft to about 300 ft above the ground. This relatively low beam height, combined with

the predominantly vertical orientation of the funnel visible in the news helicopter video of the

storm, provides considerable support for the reliability of the timings, since the radar track

closely matched the tornado ground track.

2.3 Estimated Wind Speeds and Observed Damage

There were no known direct measurements of near-surface wind speeds in the Newcastle-Moore

tornado. Wind speeds were however, estimated indirectly by the NWS using the EF Scale,23

which provides a correlation between observed damage and wind speed. Wind speed ranges

associated with EF numbers are shown in Table 2-1, and are defined as three-second peak gust

wind speeds at a height of 33 ft above the ground over open terrain.

23

Enhanced-Fujita Scale, used by the NWS to assign ratings of EF0-EF5 to tornadoes (see

http://www.spc.noaa.gov/efscale/).

N

Aerial imagery © 2013 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

Chapter 2

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 11

Table 2-1. Enhanced Fujita (EF) Scale

EF Number Wind Speed (mph)

0 65-85

1 86-110

2 111-135

3 136-165

4 166-200

5 200+

The damage path of the tornado is shown Figure 2-4, which also shows observed damage to

different buildings, trees, and other damage indicators (shown as color coded triangles on the

map, where the color indicates an EF-number based on a range of wind speeds derived from

observed damage). The NWS/NSSL survey team documented damage at several hundred

locations to determine the tornado track and intensity at different locations within the track.

Figure 2-4 also shows estimates of overall damage swaths, including small pockets of EF-4

damage just west and just east of the Canadian River. The maximum damage path width was

estimated as 1.1 miles.24

The main swath of EF-4 and above damage runs over three miles from

about South Pennsylvania Avenue east-northeast to Interstate 35 (including Briarwood and Plaza

Towers Elementary Schools and the Moore Medical Center), and then continues another two

miles farther east.

As the tornado passed through Newcastle, southern parts of Oklahoma City, and Moore, it struck

mainly residential buildings and neighborhoods. The initial touchdown location in northwest

Newcastle is very rural; damage over the first few miles of the track was primarily to trees.

Approaching the Canadian River, the tornado intensified and damaged homes and farm

buildings, and destroyed two spans of the historic 1923 trestle bridge over the Canadian River

(Figure 2-5). The damage to isolated residential buildings continued for several miles until

crossing South Western Avenue, east of which the land use is more suburban, consisting

primarily of single family residential subdivisions with neighborhood schools. At this point, the

width of the tornado damage path was approximately one mile as defined by the width of the

radar observed debris ball, with an estimated maximum intensity of EF-4 winds near the center.

Continuing east, the tornado then struck the Briarwood and Plaza Towers Elementary Schools,

and destroyed the surrounding single family residential neighborhoods. Just west of Interstate 35,

the tornado passed through a narrow commercial area, including the Moore Medical Center.

Figure 2-6 shows an aerial view of the damage to the Moore Medical Center and adjacent

residential neighborhood. The Warren Theater, located immediately south of the Moore Medical

Center, experienced only minor damage. The tornado track width narrowed to approximately a

24

NWS (http://www.srh.noaa.gov/oun/?n=events-20130520).

Ch

apter 2

12

N

IST SP 1

16

4, P

relimin

ary R

econ

na

issan

ce Rep

ort – N

ewca

stle-Mo

ore To

rna

do

Moore Medical Center

Plaza Towers School

Briarwood School

Source: NOAA/NWS. Enhancements by NIST.

Figure 2-4. Tornado damage path map showing point estimates of EF damage at specific locations (triangles) and swaths for EF-0 (turquoise), EF-1 (green), EF-2 (yellow), EF-3 (brown), EF-4 (red) and EF-5 (purple) intensity damage (data source NOAA/NWS). The

locations where damage was evaluated represents only a small percentage of the number of buildings damaged or destroyed by the tornado.

Chapter 2

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 13

Source: NOAA.

Figure 2-5. Two spans of the historic trestle bridge on US 62 running parallel to I-44 were destroyed. The bridge had been closed to traffic since 1963 but carried water pipes across the Canadian River.

half mile after crossing Interstate 35, while retaining EF-4 winds. It continued on for six miles

east of Interstate 35, as it slowly shrank and weakened while impacting primarily residential

neighborhoods.

Figure 2-7 shows EF-rated damage by the NWS/NSSL survey teams in the vicinity of Briarwood

and Plaza Towers Elementary Schools and the Moore Medical Center. NWS rated the

Newcastle-Moore Tornado as an EF-5, with maximum wind speeds of 200-210 mph based on

the damage observed at the Briarwood Elementary School.25

A multi-university team, comprised

of researchers from the University of Alabama, Mississippi State University, and the University

of Florida, estimated EF-4 damage at Briarwood Elementary School.26

Figure 2-7 shows EF-4

ratings assigned by NWS to numerous residences immediately east of Briarwood, and around the

Plaza Towers Elementary School. EF-5 damage was observed at several single family

residences immediately west of the Moore Medical Center (purple triangles in Fig. 2-7).

25

NWS (http://www.srh.noaa.gov/oun/?n=events-20130520). 26

University of Alabama (http://esridev.caps.ua.edu/MooreTornado/MooreTornado.html).

Chapter 2

14 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Source: NOAA.

Figure 2-6. Aerial view (facing east) of damage to the Moore Medical Center (upper left), with heavily damaged residential neighborhood immediately west of the Medical Center in the foreground.

Ch

apter 2

NIST SP

11

64

, Prelim

ina

ry Reco

nn

aissa

nce R

epo

rt – New

castle-M

oo

re Torn

ad

o

15

Source: NOAA/NWS. Enhancements by NIST.

Figure 2-7. EF-rated damage by NWS west of Interstate 35 in the vicinity of Briarwood and Plaza Tower Elementary Schools and the Moore Medical Center. The triangles indicate locations where damage was assessed and the triangle color indicates the EF number

assigned to each assessment. The red rectangle shows the approximate field of view of the aerial photo in Figure 2-6.

Briarwood Elementary School

Plaza Towers Elementary School

Moore Medical Center

Chapter 2

16 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

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Chapter 3

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 17

CHAPTER 3. EMERGENCY COMMUNICATIONS IN MOORE, OKLAHOMA

3.1 Emergency Communications System

Outdoor Warning System

The City of Moore’s outdoor warning system is comprised of 36 sirens which are capable of

producing alerting tones as well as both pre-recorded and live voice announcements. The

locations of these sirens are shown in Figure 3-1. According to the City of Moore Emergency

Manager,27

the sirens may be sounded for other impending dangers but their activation is usually

reserved for tornadoes. The sirens in Moore are only meant to alert/warn those located outdoors

and are used to indicate the urgent need to take shelter.

Emergency Communications

The City of Moore also has a “Code Red” Mass Notification System that sends emails, text

messages, and pre-recorded messages to phone numbers within a specified area. Additionally,

many websites, such as the Homeland Security Alerting System, provide warning notifications,

and a number of government and privately run applications will email crucial alerts to their

subscribers (City of Moore, 2012).

Furthermore, NOAA Weather Radio and Commercial Television will interrupt regular

programming to inform the Moore community about exigent emergencies, such as an

approaching tornado (City of Moore, 2012). Although television and radio broadcasts are heavily

relied upon, Smartphone Apps are often used as an auxiliary source for weather alerts (Sistek,

2013).

Warning Initiation

The Emergency Management Director, either alone or with the Police Chief, Fire Chief, City

Manager, and/or scene Incident Commander, ascertains any intelligence acquired by the

Emergency Operations Center (EOC) regarding impending danger to the City of Moore. If the

threat is determined to be real and imminent, the appropriate emergency communication system

is activated.

The Emergency Management Director has the final decision regarding the operation of the City’s

emergency warning systems. If the Emergency Management Director is unavailable, that

responsibility is devolved as follows:

• Police Chief or acting Chief

• Fire Chief or acting Chief

• Senior on-duty Police Supervisor

• Senior on-duty Fire Assistant Chief

• Senior on-duty Communications Dispatcher (City of Moore, 2012)

27

NIST Interview #1 (City of Moore Director of Emergency Management).

Ch

apter 3

18

N

IST SP 1

16

4, P

relimin

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na

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ort – N

ewca

stle-Mo

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rna

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Figure 3-1. Map showing location of sirens in Moore.

© 2012 City of Moore. Used with Permission.

Chapter 3

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 19

Emergency Detection and Preparation

Well-experienced in tornadic disasters, Moore has established an emergency operations plan and

a weather-monitoring program.28

The NWS certified Moore as “StormReady” in 2001, and the

City was most recently re-certified in 2012.29

Requirements of the program included maintaining

a 24-hour EOC; having multiple methods to receive severe weather warnings and forecasts and

to alert the public; promoting the importance of public readiness through community seminars;

and maintaining a formal hazardous weather plan, which includes training severe weather

spotters and holding emergency exercises. As a result of the tornado that occurred on May 3,

1999, Moore installed an additional 22 sirens and upgraded its 1970’s-era outdoor warning

system to new state-of-the-art sirens (Hauser 2013). Then, in 2011, additions were made

resulting in the outdoor warning system used on May 20, 2013, which consisted of 36 sirens in

total (CBS News 2013).

Official Warnings

The City of Moore also receives official or NWS-issued warning information. These official

warnings are primarily disseminated to the population via NOAA Weather Radios, the

Emergency Alert System, television and radio broadcasts (and associated mobile-based opt-in

services), social media, and Internet-based sites, including the NWS website for the Norman

WFO.

3.2 Emergency Communications on May 20, 2013

According to the NWS’s Warning Coordination Meteorologist (WCM) in the Norman WFO,

forecasters had been speaking about the possibility of severe weather for May 20, 2013 as early

as May 15, 2013. Figure 3-2 displays the seven-day forecast provided by the Norman forecast

office on Thursday, May 16, showing the potential for significant severe storms from Sunday

(May 19) to Monday (May 20). A similar forecast was also issued on Friday, May 17.

NWS also issued Hazardous Weather Outlooks as early as 5:00 am CDT on Wednesday, May

15, 2013, that mentioned the possibility of severe weather for Monday, May 20, 2013 in the

following way:

“Greater instability and wind shear will support severe storms on Sunday and

Monday…mainly over the central and eastern portions of Oklahoma.”

The Hazardous Weather Outlook issued on Thursday morning (May16, 2013) at 5:00 am CDT

provided more detailed information…

“Greater instability and wind shear will support severe storms on Sunday through

Tuesday…mainly over the central and eastern portions of Oklahoma. The latest

forecast data indicates that significant severe weather will be possible…including

destructive hail and tornadoes.”

28

NIST Interview #1 (City of Moore Director of Emergency Management). 29

City of Moore (http://www.cityofmoore.com/we-are-stormready).

Chapter 3

20 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Source: NOAA/NWS.

Figure 3-2. Seven-day forecast published on Thursday, May 16, 2013, indicating ‘Significant Severe Storms Possible’ for May 19-20.

At 8:00 am CDT on May 20, 2013, in addition to disseminating Hazardous Weather Outlooks

that day, the Norman WCM sent an email to his network of leaders inside and outside of Moore

(i.e., approximately 400 people from 56 counties and 2 states, including emergency managers,

school administrators and others) warning them about the possibility of severe weather later in

the day, and the potential for serious issues if tornadic storms occurred during school dismissal

time. An excerpt from the email reads as follows:

“We are going to be dealing with more significant storms today, including the

potential for tornadoes and giant hail. The risk for tornadoes will be highest along

and south of I-44, including the OKC metro area. We expect storms to develop a

little earlier than yesterday, maybe as soon as 1-2 pm.

This is going to create serious issues if we have tornadic storms in the area at

school dismissal time, and certainly during the afternoon drive time. Please be

sure that schools in your area are aware of this risk and that they start thinking

about what they will do if there are warnings at those critical times today.”

Additionally, at 10:00 am CDT, the Norman WCM held a weather briefing, via an online

webinar attended by over 100 emergency officials, school officials, and other community

leaders. During this webinar, he reiterated statements made in his earlier email and noted that

Chapter 3

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 21

they were expecting storms earlier than usual (i.e., during the 2 to 4 pm time-frame), which made

him concerned about school dismissal and the potential risks to safety during this time period.

However, it was not until the afternoon that severe weather watches and warnings were issued by

the WFO in Norman. The first official tornado-related emergency message was provided for

Moore on May 20, 2013 at 1:10 pm CDT in the form of a Tornado Watch. Tornado Watch 191

was valid from 1:10 pm until 10:00 pm CDT for 30 counties in Oklahoma. One of those counties

was Cleveland County, in which Moore is located.

At 2:12 pm CDT, the Norman WFO issued a severe thunderstorm warning for Northern

Cleveland County in central Oklahoma, among other areas. As shown in Figure 3-3, Moore was

almost directly in the center of that severe thunderstorm warning polygon.

Source: NOAA/NWS. Enhancements by NIST.

Figure 3-3. Severe thunderstorm warning polygon issued at 2:12 pm CDT, including Moore.

Approximately 30 minutes later, using radar data, a tornado warning was issued by the Norman

WFO (at 2:40 pm CDT) that included Moore (see Figure 3-4). The warning was issued until 3:15

pm CDT, and the text provided in the warning was as follows:

* AT 238 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS

DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A

TORNADO. THIS DANGEROUS STORM WAS LOCATED NEAR

NEWCASTLE...AND MOVING EAST AT 20 MPH.

MOORE

Chapter 3

22 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Source: NOAA/NWS. Enhancements by NIST.

Figure 3-4. Tornado warning polygon issued at 2:40 pm CDT, including Moore.

IN ADDITION TO A TORNADO...LARGE DAMAGING HAIL UP TO GOLF

BALL SIZE IS EXPECTED WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...

NORMAN...MOORE...NEWCASTLE...BRIDGE CREEK AND VALLEY

BROOK.

The 2:40 pm CDT tornado warning prompted the Emergency Management (EM) Director from

Moore to activate the outdoor siren (or alarm) system at 2:42:34 pm. The apparent two-minute

time delay in communication of the first alarm following the WFO’s warning, however, is not

accurate. Rather, this difference is due to a lack of synchrony between the clock used to track the

weather and the clock on the computer in the Moore EOC that activates the siren. The EM

Director activated the sirens immediately following the 2:40 pm NWS tornado warning in the

presence of and with approval from the City Manager.30

The Norman WFO identified the time of tornado formation to be 2:56 pm, based upon reports

from ground chasers, helicopters, and additional observation from the damage survey team. At

the same time, the outdoor siren system in Moore was activated again by the EM Director at

2:56:56 pm CDT.

30

NIST Interview #1 (City of Moore Director of Emergency Management). Times shown in this report for all

Moore siren soundings are as reported to NIST, but in actuality would have been slightly earlier due to the

difference in computer clock timings.

MOORE

Chapter 3

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 23

Approximately 5 minutes later, at 3:01 pm CDT, the Norman WFO issued a Tornado Emergency

statement.31

The Tornado Emergency was in effect until 3:45 pm and contained the following

information:

* AT 259 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS

AND STORM SPOTTERS WERE TRACKING A LARGE AND EXTREMELY

DANGEROUS TORNADO NEAR NEWCASTLE. DOPPLER RADAR

SHOWED THIS TORNADO MOVING NORTHEAST AT 20 MPH.

THIS IS A TORNADO EMERGENCY FOR MOORE AND SOUTH

OKLAHOMA CITY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING

SITUATION. IF YOU CANNOT GET UNDERGROUND GO TO A STORM

SHELTER OR AN INTERIOR ROOM OF A STURDY BUILDING NOW.

Subsequently, the sirens sounded in Moore four additional times, at 3:05:35 pm, 3:10:58 pm,

3:13:10 pm, and 3:20:18 pm CDT. Siren activation was based on Doppler radar images

available in the EOC, reports of visual confirmation of the tornado from spotters and three local

television broadcasts, and direct radio communications with the NWS. Each of the sirens

produced a steady tone for a duration of three minutes. Moore’s outdoor warning system is also

capable of transmitting pre-recorded messages from its sirens. This feature was used only once,

for the 3:10:58 pm activation, informing the Moore community that the tornado warning was still

in effect.32

Also, the Norman WFO issued two additional tornado emergency statements at 3:16

pm and 3:23 pm CDT. According to the Norman WCM, the tornado actually moved into Moore

at 3:16 pm CDT.

Based upon the tornado timeline and emergency communications timeline, outlined above, the

time between the first official NWS warning and the tornado’s contact with the ground, just west

of the Canadian River in rural northwestern Newcastle was 16 minutes. For reference, the

national average warning lead time for 2010 was 13 minutes.33

The time from the first tornado

warning until the tornado entered the City of Moore was 36 minutes.

The NWS and Moore Emergency Management Department used social networking sites such as

Twitter and Facebook to disseminate emergency information about the tornado (Bender 2013).

The City of Moore can send messages to those that have “followed” any of the City’s social

media accounts (City of Moore 2012). Additionally, the WCM in Norman mentioned his

aggressive use of social media to get word out about the Newcastle-Moore tornado. The

development of the tweets and Facebook messages was completely freeform, as there was no

specific guidance or templates available to use for emergencies, generally, or for tornadoes,

31

The warning terminology “Tornado Emergency” is reserved by the NWS for “exceedingly rare situations,” and

only where all of the following three conditions are met: (1) severe threat to human life is imminent or ongoing; (2)

catastrophic damage is imminent or ongoing; and (3) reliable sources confirm tornado, either visual confirmation or

radar imagery that strongly suggests the existence of a damaging tornado such as a debris ball signature

(http://www.nws.noaa.gov/directives/sym/pd01005011curr.pdf). 32

NIST Interview #1 (City of Moore Director of Emergency Management). 33

NOAA (http://www.noaa.gov/features/protecting/tornados101.html).

Chapter 3

24 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

specifically. The WCM created Twitter and Facebook messages using phrases such as “this is as

bad as it gets” and identifying landmarks (e.g., the Warren Theater) in one of the tweets to ensure

that individuals in the direct path of the tornado would take sheltering seriously. Also, to control

the concept of retweeting (where any messages can be re-sent by any other member of Twitter),

the tweets were manually time-stamped so that individuals would know when the tornado-related

status updates had been disseminated.

There were some issues identified by the Norman WCM regarding the use of social media in a

tornado emergency. While it is beneficial to provide building landmarks and/or cross streets in

emergency messages, it was challenging to pinpoint the tornado’s exact path . To capture

geographic information, he relied on many information sources, including the television reports

and tornado chasers. Also, due to the rapid formation and evolution of the tornado, the WCM

rarely had time to respond to any incoming messages immediately before and during the storm.

Although the City of Moore had access to their “code red” mass notification system, it was not

used on May 20, 2013. A spokesman for the City said that the sirens were decidedly more

efficient means to communicate with the public than the “code red” mass notification system

(Hauser 2013).

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 25

CHAPTER 4. BUILDING PERFORMANCE, EMERGENCY OPERATIONS, AND LIFE SAFETY OUTCOMES

This chapter focuses on the emergency operations and consequences experienced by the two

elementary schools and the medical center as a result of the Newcastle-Moore tornado. Details

are provided on occupant response, building performance, and injuries and deaths for each of the

three facilities.

4.1 Introduction

Three facilities were surveyed by the NIST Preliminary Reconnaissance team, two elementary

schools (Briarwood and Plaza Towers) and the Moore Medical Center. Figure 4-1 shows an

aerial photograph of these facilities and surroundings shortly after the tornado. All three were in

close proximity to the estimated center of the tornado damage path (shown by the red line) in

Figure 4-1. Briarwood Elementary was located in Oklahoma City, while Plaza Towers

Elementary and Moore Medical Center were located in Moore, Oklahoma. Both elementary

schools are part of the Moore Public School District. All three facilities were comprised of

several individual low-rise buildings. The buildings at the two elementary schools were one-

story in height, while the Moore Medical Center was a combination of adjoining one- and two-

story structures.

Both the Moore Public School District and the Moore Medical Center have specific emergency

action plans for tornadoes, including designated safe areas for each facility and procedures for

monitoring and responding to tornadoes. A summary of the general tornado emergency

procedures used by schools in the Moore Public School District and by the Moore Medical

Center is provided in the Appendix.

On May 20, 2013, administrators in the Moore Public Schools Superintendent’s office were

paying close attention to the threat of severe weather all day. By 9:00 am CDT, the decision was

made to cancel all afterschool activities. Morning kindergarten was released at 11:30 am CDT.

Sometime between 1:00 and 1:30 pm CDT, the decision was made to shelter-in-place (i.e., hold

all the students and faculty inside the school buildings and not run the busses).

New to the school district’s policy, and initiated on May 20, 2013, was the rule that if parents did

not have their children picked up by 2:00 pm, the students would be automatically sheltered in

the schools where they were located (normal elementary school dismissal time was 3:00 pm).

However, parents of children in Moore Public Schools that did arrive after 2:00 pm on May 20,

2013 were allowed to pick up their children, if so desired.34

Some family members arrived at

schools so late in the storm that they perceived no other option than to shelter with their children

at the school.

34

NIST Interview #20 (Assistant Superintendent, Moore Schools).

Chapter 4

26 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

According to the Assistant Superintendent of Moore Public Schools, at 2:15 pm CDT, the storms

started to hit west of Newcastle. All schools (kindergarten through high school) were told to

evacuate all people from the outbuildings (i.e., those buildings in which no designated shelter

areas were identified) and move them into other buildings on the school campus. Around 2:40

pm CDT, when the first tornado warning was issued by NWS, the school district instructed all

schools that everyone should move to their safety positions.

Figure 4-1. Aerial overview, after the tornado, showing NIST-surveyed facilities relative to the estimated

center of the tornado damage path (red line).

4.2 Plaza Towers Elementary School

Facility and Tornado Sheltering Plan Description

Plaza Towers Elementary School was constructed in the 1970s with one original main classroom

building. Later additions included a Gymnasium building, a new main classroom building

(stand-alone), a Media building (connected to the original main classroom building), and four

portable classroom buildings (see Figure 4-2). All Plaza Towers’ buildings were one-story

structures. Despite media reports to the contrary, none had a basement or below-ground level.

The buildings were one of the following common structural systems:

Box-type system (BTS) with reinforced concrete masonry unit (CMU) perimeter walls

laterally braced by a metal roof system that consisted of wide-rib metal roof decks

N

© 2013 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 27

covered with rigid thermal insulation and supported by open-web steel roof joists (new

main classroom building).

Light steel frame (bolted W-shape beams and circular columns) supporting a metal roof

system with perimeter reinforced CMU walls (original main classroom and Media

buildings).

Pre-engineered rigid steel frame cladded with perimeter reinforced CMU walls

(Gymnasium building).

The school’s tornado emergency procedures designate areas of safety in the original and new

main classroom buildings (locations shown in Figure 4-3). Within the original main classroom

building, students were primarily instructed to move from external classrooms into the interior

hallway areas. Each classroom had a specific location within the main interior hallways where

shelter should have been taken. Additionally, occupants of the Gymnasium building were

instructed to travel to the original main classroom building for shelter (in the interior hallway).

Occupants of the portable classroom buildings were also directed to move into the original main

classroom building for shelter in the interior hallway. In the new main classroom building,

individuals were instructed to shelter in the interior hallway and the girls and boys bathrooms.

Figure 4-2. Aerial photograph of Plaza Towers Elementary School prior to the tornado.

Original Main

Classroom Building

New Main

Classroom Building

Gymnasium

Media Building

Portable Classroom

Building

N

© 2012 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

Chapter 4

28 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 4-3. Designated areas of safety for tornadoes for the Plaza Towers Elementary School. The

yellow shaded areas indicate the locations of bathrooms also used for shelter on May 20, 2013. The area shaded in red indicates where seven school children died.

Emergency Operations, Facility Performance, and Life Safety Outcomes

At Plaza Towers Elementary School, NIST obtained first-hand accounts of the emergency

response from three teachers who were located on the northeast side of the original main

classroom building. Before the tornado hit, teachers, school staff, and students received

instructions to take cover, i.e., to initiate their tornado procedures, via the school-wide public

address announcement system. Teachers then led their students to shelter in the designated

locations, which included both internal hallways of the building (i.e., the north-to-south hallways

and the east-to-west hallway as shown in Figure 4-3). The number of students within the Original

New Main Classroom

Building

Portable Classroom Buildings

Gymnasium

Original Main

Classroom Building

Media

Building

Legend

Approximate locations of: Building walls

Hallways

Tornado Safety Areas

Additional areas used for sheltering on May 20, 2013

Location of seven school children deaths

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 29

Main Classroom Building was reduced, since many students had been picked up by family

members earlier that day.35

Whereas media articles claimed that some students were bused from Plaza Towers before the

tornado hit, teachers interviewed for this study disputed those claims.36

Some students were

picked up by their families prior to the tornado strike, and all remaining students took shelter

inside the elementary school. It was only after the tornado was over that students, teachers, and

school staff walked to a nearby church.

As students and teachers in the original main classroom building remained in their shelter

locations, another teacher was observing the tornado approaching from an exterior window of the

school.37

As the skylights in this teacher’s hallway (on the northeast corner of the original main

classroom building) where the students were taking refuge began getting sucked up into the

tornadic winds, this teacher instructed students and school staff to take refuge in the nearby

bathrooms immediately. The teacher made this decision because the teacher felt that the hallways

would not be safe enough for the children. The students and teachers in this group dispersed

among the two main bathrooms and closet in the northeast section of this building, shown in

yellow in Figure 4-3 (with 25 to 30 students and teachers in each bathroom, and more in a closet

between the bathrooms) moments before the roof was blown off of the school. Overall, in the

original main classroom building, staff, teachers and students ended up taking shelter in the

hallways that ran east-west only (and not in the hallways that ran north-south) as well as the

restrooms off of the east-west hallways. Minimal debris came down in the bathrooms and closet,

but adjacent hallways were buried under several feet of debris, high enough that the teacher

could stand on the debris and reach over the top of the wall to help extricate students from the

bathrooms and closet. The debris in the hallway in the northwest part of the building was only 2

to 3 ft deep, but also included a vehicle.

The buildings of Plaza Towers Elementary School sustained significant structural damage due to

strong wind and debris impact loadings. Figures 4-4 and 4-5 show aerial views of Plaza Towers

Elementary School shortly after the tornado hit. Following is a summary of the damage observed

at this facility and related fatalities and injuries.

35

NIST Interview #19 (Teacher, Plaza Towers Elementary School). 36

Ibid. 37

NIST Interview #13 (Teacher, Plaza Towers Elementary School).

Chapter 4

30 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 4-4. Aerial photograph of Plaza Towers Elementary School and proximity to estimated center of tornado damage path.

Source: NOAA. Enhancements by NIST.

Figure 4-5. Post-tornado aerial view (looking northeast) of the Plaza Towers Elementary School taken May 21, 2013. Much of the debris had already been moved by the time of this photograph as part of

the search and rescue operations. The area circled in red shows the approximate location in the hallway of the new main classroom building where the 7 fatalities occurred.

N

© 2013 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 31

This area was a “designated area of safety” according to the school’s tornado emergency

procedures (location shown on Figure 4-3). Five of the seven children died after the west

masonry hallway wall collapsed on them. The east hallway wall also collapsed into the

hall, but in such a manner as to leave an area of void space. Two fatalities occurred along

the eastern wall, and seven or eight students and one teacher were rescued from under the

rubble in that area as well.38

According to the school principal,39

injuries suffered in this

building included a head injury to a staff person, a sternum fracture to a teacher, and a

puncture wound in the back to a student; and at least one of the three injured was reported

to be located in the “designated area of safety”.

Original main classroom Building: A portion of the building (southwest wing)

sustained complete structural failure with loss of the metal roof system (i.e., failure of

joist-to-wall anchors) and collapse of the reinforced CMU perimeter walls (Figure 4-7).

Other portions of the building sustained partial roof loss, but the building did not

collapse. This was likely due to the redundancy of the steel frame system, which does

not rely solely upon lateral bracing by the roof for stability. The un-collapsed portion of

the building sustained significant damage to the interior (Figure 4-8) due to damage to the

building envelope (i.e., broken windows and missing sections of the roof). An interview

with a teacher who sheltered in a bathroom near the northeast corner of the building

confirmed that the structural failure sequence first involved the roof system being blown

off before the walls started to collapse.40

In the front hallway to the west of the Main

Office, a toddler suffered a broken leg and a teacher suffered a fractured pelvis and was

hospitalized. Additionally, a teacher in one of the restrooms sustained tendon damage to

the wrist.41

Gymnasium building: The gymnasium side (west side) of the building was largely

demolished, with the collapse of the structural frame and most of the perimeter reinforced

CMU walls, as shown in Figure 4-9. The loss of the building envelope resulted in

significant damage to the interior of the portions of the building that did not collapse.

The interior reinforced CMU walls that surrounded the Gymnasium Office remained

intact and offered some protection and safe shelter against debris impact, despite having

also lost their roof system. No one took shelter in the gymnasium before or during the

tornado.42

38

Ibid. 39

NIST Interview #21 (Principal, Plaza Towers Elementary School). 40

NIST Interview #13 (Teacher, Plaza Towers Elementary School). 41

NIST Interview #21 (Principal, Plaza Towers Elementary School). 42

Ibid.

Chapter 4

32 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 4-6. Damage to the hallway and classrooms of the new main classroom building (complete loss of

roof and many walls) where the 7 fatalities occurred (most of the debris has already been removed). This hallway area was a “designated area of safety.”

Figure 4-7. Collapsed southwest wing of original main classroom building.

Room 51

Room 52

Room 53

Room 57

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 33

Figure 4-8. Damaged interior of a classroom in the original main classroom building.

Figure 4-9. Collapsed Gymnasium building (Note the interior Gymnasium Office surrounded by a reinforced CMU wall remained standing).

Chapter 4

34 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

4.3 Briarwood Elementary School

Facility and Tornado Sheltering Plan Description

Figure 4-10 shows an aerial view of the buildings at Briarwood Elementary School before the

tornado. The school comprised of four main classroom buildings (designated 100 to 400), six

portable classroom buildings (together designated as 500 buildings), a cafeteria building, and a

multipurpose building that housed a basketball court, a music classroom, an art classroom, and a

set of bathrooms. All were one-story buildings. The structural damage at this school was cited

as the reason for the EF-5 rating of this tornado by the NWS/NSSL survey team.

Figure 4-10. Aerial overview of the Briarwood Elementary School before the tornado.

The buildings at Briarwood Elementary School were constructed of two common structural

systems. The four main classroom buildings (buildings 100 to 400) and the Cafeteria were BTS

with reinforced CMU perimeter walls supporting (and laterally braced by) a metal roof system

that consisted of wide-rib steel roof decks connected by puddle welds to open-web steel roof

joists. The perimeter reinforced CMU walls were clad with a layer of exterior brick façade. The

multipurpose building, built in 2002, employed a combined system of pre-engineered rigid steel

frames (tapered built-up plate sections) supporting cold formed “Z”-shaped roof purlins and a

metal roof deck, with reinforced CMU perimeter walls.

Figure 4-11 shows the designated tornado safety area locations within each building at

Briarwood Elementary school, where students and teachers/staff were to take shelter in a tornado

Multipurpose

300

200

400

100

Cafeteria

500

N

© 2012 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 35

event. In most buildings, students and teachers/staff were instructed to leave external

classrooms and move to the main interior hallways. In the 100 building, the interior hallways

surrounding the central teacher’s lounge area were the designated safety areas. The multipurpose

building did not contain any designated safety areas, and therefore, occupants were instructed to

return to their homerooms in the event of a tornado. Occupants of portable classroom buildings

(500) were instructed, by this plan, to enter the nearest building (either the 300 or 400 building)

for shelter.

Figure 4-11. Tornado safety areas for Briarwood Elementary School. The students and staff generally sheltered according to the tornado plan (hatched areas), but, as described in the text, some used the

bathrooms in the 400 building (yellow shaded area).

Legend

Approximate Locations of:

Building walls

Hallways

Tornado Safety Areas

Additional areas used for

sheltering on May 20, 2013

400

100

Cafeteria

200

300

500

Multipurpose Building

Chapter 4

36 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Emergency Operations, Facility Performance, and Life Safety Outcomes

NIST obtained first-hand accounts of the emergency response on May 20, 2013 from the

principal and from two teachers who were located in the 400 building before and during the

tornado. The teachers indicated about two thirds of the students were picked up early by their

parents, leaving around 8 to 10 students per class, compared with a typical class size of 25.

School staff, teachers, and students received instructions to take shelter over the school’s

intercom or public address system. According to one teacher, the principal told them to “take

your tornado precautions…this is not a drill”43

. The teachers then instructed their students to get

into the designated shelter areas, as shown in Figure 4-11. The 5th

and 6th

grade students, located

in the 400 building, initially took shelter in the main hallway and were told to get down into the

safety position. However, after students took refuge in their designated shelter areas, against the

newly initiated school policy for shelter-in-place, teachers noted that parents were still arriving at

the school to pick up their children.44

In other parts of the school campus, shelter spaces

identified in Figure 4-11 were used generally according to plan, although three of the 3rd

grade

classes from the 300 building were moved to the 400 building. In the 200 building, 1st graders

moved their desks into the designated hallway and got under the desks.45

As the tornado traveled closer, the teachers took notice. One teacher in particular, located in the

400 building, stood at a window and observed the tornado heading directly for Briarwood

Elementary. At this moment, the teacher decided that the situation was worse than any of them

had originally anticipated and told the other teachers to get their students into the bathrooms

(yellow shaded area in Figure 4-11).46

Figure 4-12 shows one of the bathrooms used for shelter

in the 400 building. According to interviews with teachers in that building, 20 to 30 children

were located in each bathroom (the boys’ and the girls’ bathrooms) in addition to a few parents

and the teachers of the students who held class in that building. The ceiling tiles and insulation

fell onto the children and adults sheltering in the bathrooms but caused no injuries. Despite

extensive damage to or total collapse of most of the buildings at Briarwood Elementary, there

were no fatalities at the school.47

Two teacher’s assistants were injured in the 100 Building, one

suffering broken ribs and cheekbone, and another impaled through the leg.48

The buildings of Briarwood Elementary School sustained significant structural damage due to

strong wind and debris impact loadings. Figure 4-13 show an aerial view from the morning after

the tornado struck. Following is a summary of the damage observed at this facility.

43

NIST Interview #15 (Teacher, Briarwood Elementary School). 44

NIST Interview #14 (Teacher, Briarwood Elementary School). 45

NIST Interview #22 (Principal, Briarwood Elementary School). 46

NIST Interview #15 (Teacher, Briarwood Elementary School). 47

NIST Interview #23 (Captain, Oklahoma City Fire Department). 48

NIST Interview #22 (Principal, Briarwood Elementary School).

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 37

Figure 4-12. Bathrooms used for shelter in the 400 building of Briarwood Elementary School.

Figure 4- 13. Aerial photograph of Briarwood Elementary School and proximity to estimated center of

tornado damage path (red line).

© 2013 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

© 2013 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

N

Briarwood Elementary School

Building 100

Building 400 Building 300

Cafeteria Building

Building 200

Building 500

MultipurposeBuilding

Chapter 4

38 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Multipurpose Building: This pre-engineered rigid steel frame building sustained

complete structural failure, with the collapse of all the steel frames and three of the four

perimeter reinforced CMU walls (see Figure 4-14).

300 Building: This BTS building sustained complete structural failure with the loss of

the metal roof system and partial collapse of perimeter reinforced CMU walls. The

building was also impacted by large windborne debris, including automobiles and a large

propane tank labeled as belonging to a farm located half a mile west-northwest (see

Figure 4-15). The tank was 20 ft long, 7 ft in diameter, with an empty weight of 10 tons

(fuel level unknown).

200 Building: This BTS building sustained complete structural failure with the loss of

the metal roof system and collapse of all perimeter reinforced CMU walls (Figure 4-16).

Similar to the 300 Building, this building was also impacted by large windborne debris

(automobiles). The only spaces within this building that did not collapse completely

were the boys’ and girls’ bathrooms, which were surrounded by interior reinforced CMU

walls. The bathrooms did provide some safe shelter despite complete loss of the roof

system.

Cafeteria: Similar to the 200 Building, the cafeteria building sustained complete

structural failure with the loss of the metal roof system and collapse of all perimeter

reinforced CMU walls. The only area that remained standing was the boys’ and girls’

bathroom area (see Figure 4-17).

100 Building: This building was a BTS building with a steel roof framing system.

Damage included disconnection and displacement of the steel roof framing system and

partial collapse of the reinforced CMU perimeter walls.

400 Building: This BTS building, shielded to some extent by the 300 and 200 buildings

from the west and the 100 building from the south, sustained the least structural damage

compared with the rest of the school buildings. Damage included the loss of a small

section of the roof, with the perimeter reinforced CMU walls remaining essentially intact.

However, the damage to the building envelope (i.e., roof and windows) also led to

significant damage to the interior of this building. Figures 4-18 and 4-19 show interior

views of a classroom and a hallway in the 400 Building after the tornado.

500 Buildings: Portable buildings housing classrooms 501-506 were completely swept

away from the site.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 39

Figure 4-14. Collapsed Multipurpose Building of Briarwood Elementary School.

Figure 4-15. Building 300, with propane storage tank (white) that landed on top.

Chapter 4

40 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 4-16. Building 200 (completely demolished, with only the boy’s and girl’s bathrooms remaining standing).

Figure 4-17. Cafeteria. Complete structural failure with only the interior bathroom remaining standing.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 41

Figure 4-18. An interior view of a classroom in the 400 Building where portion of the building’s metal roof system was lost.

Figure 4-19. Hallway of Building 400 after the tornado (designated tornado safety area and initial location of Building 400 occupants before moving to the bathrooms just before the tornado struck)

Chapter 4

42 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

4.4 Moore Medical Center

Facility and Tornado Sheltering Plan Description

The Moore Medical Center is part of a health care system called Norman Regional Health Care.

The original facility was constructed in 1988 and consisted of the North Medical Office Building

(North MOB). The North MOB was a two-story precast concrete structure, with a precast

concrete second floor and roof. In 2002, a two-story, steel frame building was added to the

facility. The newly added building consisted of a 45-bed hospital (center section) and the South

Medical Office Building (South MOB).49

The structural system consisted of a steel braced frame

(for lateral load resistance) with simple shear beam-to-column connections, cladded by

reinforced CMU and brick curtain walls, and a metal roof system (for gravity load resistance)

that consisted of open-web steel joists supporting a metal roof deck covered with rigid thermal

insulation. The first story of the 2002 building has a larger plan area than the second story.

According to the Medical Center’s “Code Black Plan” for emergencies, the tornado sheltering

procedure was to move all bed patients away from external locations throughout the medical

center into interior hallways (away from windows). Ambulatory patients and visitors were to be

relocated to a “designated protected area,” which was the first floor cafeteria in the hospital.

Emergency Operations, Facility Performance, and Life Safety Outcomes

In terms of the tornado emergency procedures for this hospital, the Manager of Safety for Moore

Medical Center,50

who also has safety/security responsibility for Norman Regional Hospital and

Healthplex (both located in Norman), and the Executive Secretary from Moore Medical Center51

provided the following information on the events that took place on May 20, 2013 inside Moore

Medical Center.

On May 20, 2013, although the medical center had capacity for 45 patients, one entire wing of

the hospital was empty, and only 13 patients (not including newborn babies) were located in the

hospital that day. The following outlines the emergency communications timeline on May 20,

2013 for Moore Medical Center:

1:53 pm CDT: “Code Black Watch”52

was issued by the Manager of Safety for Moore

Medical Center for all Normal Regional Health System locations (including Moore

Medical Center).

2:20 pm CDT: “Code Black Warning” was issued by the Manager of Safety for Moore

Medical Center for all Normal Regional Health System locations (including Moore

Medical Center).

49

Plans for the 2002 addition reflect that it was designed to the 1996 edition of the National Building Code (BOCA

1996), having wind design parameters as follows: 80 mph fastest-mile basic wind speed; exposure category B; and

1.15 importance factor. 50

NIST Interview #10 (Manager of Safety, Moore Medical Center). 51

NIST Interview #24 (Executive Secretary, Moore Medical Center). 52

See Appendix for more information on watch, warning, and alert as used by the Normal Regional Health System.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 43

Figure 4-20. Aerial photograph of Moore Medical Center before the tornado.

2:34 pm CDT: “Code Black Alert” was issued by the Manager of Safety for Moore

Medical Center for Moore Medical Center. When the Manager of Safety was asked why

he issued the “Code Black Alert” at 2:34 pm CDT, even before a tornado warning was

issued by NWS (at 2:40 pm CDT), he could not say why he made that decision.

According to the Manager of Safety, he just had a feeling that he should issue the “Code

Black Alert” for Moore Medical Center.

2:40 pm CDT: NWS issues a tornado warning that included the city of Moore.

2:44 pm CDT: “Code Black Alert” issued by the Manager of Safety for Moore Medical

Center for Healthplex and Norman Medical Center (however, the “Code Black Alert”

was not recorded at Norman Medical Center, and the text for the alert was not received

due to the storm until 7:37 pm CDT).

Around 3:16 or 3:17 CDT: The Executive Secretary for Moore Medical Center, who was

monitoring the tornado by local news (television), emails (from City of Moore’s

Emergency Management Director), the YouTube briefing by the Norman WCM, and the

hospital emergency warning system through communication with the hospital’s Manager

of Safety (regarding Code Black Watches, Warnings, and Alerts), received a unique

“Code Yellow” overhead page also from the Manager of Safety. A “Code Yellow” alert

is the hospital’s “Disaster Preparedness Code,” and the Executive Secretary perceived

this page as meaning that conditions had become serious; i.e., that a tornado was headed

right for them.

3:21 pm CDT: A tornado strikes the Moore Medical Center.

N © 2012 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

North

MOB

South

MOB

Hospital

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44 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Once the “Code Black Alert” was issued for Moore Medical Center at 2:34 pm CDT, the

procedure was to move all bed patients from external locations throughout the facility into

interior hallways (away from windows). On May 20, 2013, the Manager of the Family Birth

Center and the Manager of Med Surg/Peds/PCU decided that patients and staff should relocate to

certain areas on the first floor. This decision was made for two reasons: 1) both managers were

feeling uneasy about the weather; and 2) there were reports from weather stations that there was

a tornado on the ground at Newcastle.53

Before the tornado hit, with the exception of one patient

in the Labor and Delivery Department and a few staff members assisting her,54

all patients and

hospital staff relocated to the first floor of the hospital. According to the medical center’s

Executive Secretary, patients, hospital staff, and community members generally took refuge in

accordance with the Medical Center’s emergency plan with the following exceptions:

One group of 5 to 6 people was located in the Imaging Department.

One large group, including most hospital patients, took refuge in the cafeteria, according

to the emergency plan. However, upon the receipt of the Code Yellow alert, the

Executive Secretary, who was also located in the cafeteria, decided to instruct all

physicians to relocate from the cafeteria to the walk-in refrigerator (located in a room

adjacent to the cafeteria, but still internal to the hospital). The Executive Secretary made

this decision to further protect the physicians because she thought that the physicians and

their skills might be required during the recovery stages of this tornado.

A larger group from the City of Moore (i.e., individuals who were not originally located

at the medical center, but traveled to the medical center for shelter) was located outside of

the cafeteria doors in the surrounding hallways.

All of the shelter areas were interior spaces, mostly surrounded by interior reinforced CMU.

Despite extensive damage to the building exterior and much of the interior, none of the areas

where people took shelter sustained significant damage, and according to official sources at the

Moore Medical Center, no deaths or injuries due to the effects of the tornado occurred in this

building on May 20, 2013.

The estimated centerline of the tornado damage path passed close to the center of the facility

(Figure 4- 23). The damage across the entirety of the exterior of the Moore Medical Center is

shown in Figs. 4-24 through Figure 4-26. The figures show severe damage to much of the

interior of the hospital and the medical office buildings. Similar to the two elementary schools

discussed earlier in the report, the Moore Medical Center was also subjected to both wind and

wind-borne debris impact loading; however, the structural damage to the Medical Center was

minimal compared to the schools. Debris hazards included automobiles (and automobile parts)

tossed against, into, and onto the building, and a large steel trash dumpster that landed on top of

the second story of the west nursing wing of the hospital, damaging the roof deck and supporting

bar joists (Figure 4-28).

53

NIST Interview #24 (Executive Secretary, Moore Medical Center). 54

One patient was in labor and had already received her epidural and so she had to stay on the second floor in the

Labor and Delivery Department. The patient was with a few nurses, who covered her during the storm. The tornado

did take out a wall where they were located, but they did not receive any injuries from the storm.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 45

Other damage sustained by the Moore Medical Center included:

Partial loss of roof system in isolated areas including disconnection of metal roof deck

and/or joist-to-frame connections on both the first and second stories (see circled areas in

Figures 4-24 and 4-28)

Extensive damage to roof architectural elements and partial loss of roof coverings

(Figures 4-24 and 4-25)

Significant damage to the building envelope, including collapse of curtain walls, broken

window glazing, broken exterior doors, damaged wall cladding, etc. (Figures 4-24 and 4-

26)

Significant damage to the building interior, including damaged partition walls, suspended

ceiling systems, furniture, equipment, and building systems (e.g., electrical, lighting,

plumbing, heating, ventilation and air conditioning, communications, and others) as

shown in Figure 4-27

A high level of damage to interior doors, even in areas where the overall level of interior

damage was not very intense. All of the observed broken interior doors were constructed

of particle board (Figure 4-29).

The damage to the building envelope systems, and subsequent damage to the interior

construction, contents, equipment, and building systems due to wind, rain, and debris penetration

deep into the buildings caused the Moore Medical Center to suffer a complete loss of

functionality. Despite the fact that the structural frame system of the building remained largely

intact, the entire facility was demolished, leaving the City of Moore without a hospital.

Figure 4-21. Cafeteria located on the first floor interior of the Moore Medical Center hospital where patients sheltered during the tornado.

Chapter 4

46 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 4-22. Physicians were relocated from the cafeteria to these walk-in freezers for anticipated additional level of protection for staff that would be needed for response and recovery.

Figure 4-23. Aerial photograph of Moore Medical Center shortly after the tornado struck, showing estimated centerline of the tornado damage path (in red).

N © 2013 Bearing Tree Land Surveying. Used with Permission. Enhancements by NIST.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 47

Source: NOAA. Enhancements by NIST.

Figure 4-24. Aerial view of the heavily damaged Moore Medical Center (looking south-east). Circled locations indicate areas of roof deck damage.

Figure 4-25. Damage to the building envelope and rooftop architectural elements of Moore Medical Center.

N

Chapter 4

48 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Figure 4-26. Damage to the envelope of Moore Medical Center (glazing).

Figure 4-27. Damage to the interior of the Moore Medical Center due to wind and debris infiltration.

Chapter 4

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 49

Figure 4-28. Impact damage to hospital roof bar joists from steel trash dumpster, and loss of steel roof

decking.

Figure 4-29. Examples of broken interior doors at the Moore Medical Center.

Chapter 4

50 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

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Chapter 5

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 51

CHAPTER 5. OBSERVATIONS

Observations based on data and information collected during the course of this Preliminary

Reconnaissance are presented below. They are arranged in five groups, the first three providing

context, and the last two addressing the specific objectives of the Preliminary Reconnaissance.

Tornado History and Preparedness

The City of Moore (and surrounding areas) have had much experience in recent years

with tornado disasters, including strikes by one F-2, two F-4/EF-4, and two F-5/EF-5

tornadoes since 1998 (a Fujita Scale F-2 tornado in 1998, an F-5 tornado in1999, an F-4

tornado in 2003, an Enhanced Fujita Scale55

EF-4 tornado in 2010, and the May 20, 2013,

Newcastle-Moore EF-5 tornado). Moore is one of just a few communities nationwide to

have ever been struck by two F-5/EF-5 tornadoes.

Moore’s work to prepare for tornadoes has included implementing storm monitoring and

education and training programs, becoming a NWS certified StormReady Community in

2001, and maintaining that certification since. It was most recently recertified in 2012.

Elements of the program include maintaining a 24-hour emergency operations center;

having multiple methods to receive severe weather warnings and forecasts and to alert the

public; promoting the importance of public readiness through community seminars; and

maintaining a formal hazardous weather plan, which includes training severe weather

spotters and holding emergency exercises.

While some research has shown that high false alarm rates can contribute to complacency

by the public in response to warnings, the false alarm rate for official tornado warnings in

Moore in recent years was considerably lower than the national average. During the era

of storm-based warning polygons (as opposed to earlier county-wide warnings), between

October 2007 and May 19, 2013, 16 official tornado warnings were issued for all or some

parts of Moore, 12 of which were followed by verified tornadoes. This yielded a false

alarm rate for the Moore area of 25 percent (4 false alarms out of 16 warnings), compared

to the national average false alarm rate of 74 percent for 2010.

Building Codes and Storm Shelters

Moore had adopted national model codes governing design and construction of buildings,

and was enforcing the 2009 International Code Council (ICC) International Building

Code (IBC) and the 2009 ICC International Residential Code for One- and Two-Family

Dwelling (IRC) at the time of the Newcastle-Moore tornado.

Tornadoes are not explicitly considered in either the 2009 IBC or 2009 IRC for any types

of buildings, except storm shelters. Although design wind speeds required by those

55

The National Weather Service (NWS) switched from rating tornado intensity using the Fujita Scale to the

Enhanced Fujita Scale in 2007 (see Section 2.3 for more information).

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52 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

codes are in the range of EF-1 tornadoes, the codes do not address potentially greater

lateral and roof uplift pressures in tornadoes compared to other types of windstorms, and

do not address windborne debris, which is a significant contributor to building damage in

tornadoes.

There were no public or community shelters in Moore at the time of the Newcastle-

Moore tornado. The City’s strategy was to recommend shelter-in-place, except for

occupants in mobile homes or portable buildings, who were advised go to a substantial

structure. The City’s stated rationale was twofold: there were no public buildings having

a suitable location for a shelter; and the overall risk was less to shelter-in-place in a

reasonably well-constructed residence (considering available warning time, travel time to

a shelter, traffic, and other factors).

Over 3,000 residential shelters have been constructed in Moore and were registered with

the city at the time of the Newcastle-Moore tornado, perhaps the highest number of

residential shelters per capita in the U.S.

Installation of storm shelters in homes or other buildings is strictly voluntary; neither the

national model building codes adopted by Moore nor local amendments require storm

shelters.

Events Immediately Prior to the Tornado

The threat of severe weather for the Moore area on May 20, 2013, was identified as early

as May 15 by the NWS Storm Prediction Center (SPC). The Hazardous Weather

Outlook on May 15 indicated the possibility of severe storms on May 19-20, which was

expanded to include possible destructive hail and tornadoes in the May 16 Outlook. The

Convective Outlook issued at 1:00 am CDT on May 20 indicated a 10% or greater

probability of EF2-EF5 tornadoes occurring within 25 miles of a point for the central

Oklahoma region on the afternoon of May 20.

The tornado touched down while Moore schools were still in session. However, many

parents had picked up their children earlier in the day in response to increasing concerns

about the weather, significantly reducing the number of students at the schools when the

tornado struck. Due to the threat of severe weather that afternoon, Moore Public Schools

made the decision by 9:00 am CDT to cancel all afterschool activities on May 20. By

1:30 pm, the decision was made to shelter-in-place (i.e., not run the buses or release the

students at the normal 3:00 pm dismissal time).

Observations on Objective 1: Performance of the emergency communications systems

immediately prior to and during the tornado

The NWS Weather Forecast Office (WFO) in Norman made extensive use of

nontraditional communications on May 20 to provide more frequently updated

information about the possibility of severe weather and about the tornado warnings.

Chapter 5

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 53

These new communication methods included recorded severe weather briefings on

YouTube, direct emails to stakeholders (e.g., emergency managers, school

administrators), and Twitter and Facebook posts.

The first official tornado warning for the Moore area was issued at 2:40 pm CDT, and the

tornado touched down at 2:56 pm, for a lead time of 16 minutes. The 2010 national

average tornado warning lead time is 14 minutes (latest available data). The leading edge

of the tornado reached Briarwood Elementary School at approximately 3:15 pm, Plaza

Towers Elementary School a few minutes later, and the Moore Medical Center at

approximately 3:20 pm.

An official Tornado Emergency warning, the most urgent official warning type, was

issued by NWS at 3:01 pm CDT. This terminology, reserved by NWS for “exceedingly

rare situations,” had only been used twice previously by the Norman WFO, for the 1999

F5 and the 2003 F4 tornadoes, both of which struck Moore and surrounding areas.

The tornado sirens in Moore were sounded six times. The initial siren was sounded

shortly following the first NWS tornado warning at 2:40 pm CDT, and the last at

approximately 3:20 pm. The sirens in Moore are only meant to alert/warn those located

outdoors and are used to indicate the urgent need to take shelter. Moore’s outdoor

warning system is also capable of transmitting pre-recorded messages from its sirens.

This feature was used only once, for the 3:11 pm activation, informing the Moore

community that the tornado warning was still in effect.

Observations on Objective 2: Response of critical and educational facilities (specifically, the

Moore Medical Center and Briarwood and Plaza Towers Elementary Schools) to the tornado,

including emergency operations, the physical performance of the buildings and designated

safe areas, and life safety outcomes.

At both Briarwood and Plaza Towers Elementary Schools, most designated tornado safe

areas were severely damaged or destroyed. Some of the designated safe areas at the

Moore Medical Center had significant damage due to collapse of interior walls and

ceilings on the second floor and due to infiltration of windborne debris in hallways on the

first floor. None of these buildings had facilities specifically designed for use as storm

shelters56

or safe rooms,57

and none had basements.

The designated safe areas in the new main classroom building at Plaza Towers

Elementary School did not provide life safety. Seven schoolchildren died when part of

the building’s designated safe area, in which they were located, collapsed. Two adults

and one student were also significantly injured in the new main classroom building. No

fatalities occurred in the original main classroom building at Plaza Towers Elementary

School; however, two teachers and one child suffered significant injuries.

56

As defined by the ICC 500 Standard for the Design and Construction of Storm Shelters (ICC, 2008). 57

As defined by FEMA 361, Design and Construction Guidance for Community Safe Rooms (FEMA, 2012)

Chapter 5

54 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

Extensive damage to the building envelope of the Moore Medical Center allowed wind,

debris, and water inside the building, causing severe damage to the interior and rendering

the hospital and medical office buildings completely nonfunctional. Damage to the

structural systems (pre-cast concrete and steel framing) was negligible.

There were no reported fatalities at Briarwood Elementary School or Moore Medical

Center. Two teacher’s assistants suffered significant injuries at Briarwood Elementary

School (in the 100 Building) and no significant injuries were reported at Moore Medical

Center.

For the most part, designated safe areas as identified in emergency plans were used at the

three facilities surveyed by NIST. In some cases, last-minute decisions were made to use

smaller interior spaces or rooms, which were not previously identified in the building’s

emergency plans as designated safe areas, such as bathrooms and closets in the two

elementary schools and a walk-in freezer in the Moore Medical Center.

Smaller interior spaces (e.g., bathrooms) surrounded by reinforced masonry (CMU) walls

at both schools performed better when compared with adjacent hallways and classrooms.

The CMU walls that surrounded these interior spaces were found to more often remain

standing and thereby provide some protection against wind-borne debris.

Multiple buildings at both elementary schools suffered complete collapse or severe

damage. The elementary school buildings with box-type construction typically sustained

loss of the roof system and diaphragm, leading to partial or total collapse of the

supporting walls. Pre-engineered metal gymnasium and multipurpose buildings sustained

total structural failure.

References

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 55

REFERENCES

Bender, C. (May 21, 2013). Bloomberg. Oklahoma tornado alert gave residents 36 minutes

warning. Retrieved from http://www.bloomberg.com/news/2013-05-21/tornado-alert-gave-

moore-oklahoma-residents-36-minutes-warning.html.

BOCA (Building Officials and Code Administrators International, Inc.). (1996). National

Building Code. Country Club Hills, IL.

City of Moore. (2012). Emergency Operations Plan, Moore Oklahoma. Retrieved from

http://www.cityofmoore.com/sites/default/files/main-

site/2012%20Emergency%20Operations%20Plan.pdf.

Cliff Mass Weather Blog. (May 21, 2013). The Lessons of the Moore Oklahoma Tornado.

Retrieved from http://cliffmass.blogspot.com/2013/05/the-lessons-of-moore-oklahoma-

tornado.html.

FEMA (Federal Emergency Management Agency). (2012). Spring 2011 Tornadoes: April 25–

28 and May 22, Building Performance Observations, Recommendations, and Technical

Guidance. Mitigation Assessment Team Report. FEMA P–908. Washington, DC, May.

FEMA (Federal Emergency Management Agency). (2013). Senior Leadership Briefing,

Oklahoma Tornadoes 2013, Thursday, May 23, 2013 (6:00 p.m.) FINAL.

Fernandez, M. Healy, J. (May 21, 2013). The New York Times. Drama as alarm sirens wailed.

Retrieved from http://www.nytimes.com/2013/05/22/us/oklahoma-

tornado.html?pagewanted=all&_r=0.

Haan, F., Jr., Balaramudu, V., and Sarkar, P. (2010). ”Tornado-Induced Wind Loads on a Low-

Rise Building.” J. Struct. Eng., 136(1), 106–116.

Hauser, A. (May, 31, 2013). Is Moore, Okla. Ready for Another Tornado? The Weather Channel.

Retrieved from http://www.weather.com/news/tornado-central/moore-okla-ready-another-

storm-20130529.

ICC (International Code Council). (2008). ICC/NSSA Standard for the Design and

Construction of Storm Shelters. ICC 500–2008, American National Standard. Washington,

DC, June.

ICC (International Code Council). (2009a). International Building Code. Falls Church, VA.

ICC (International Code Council). (2009b). International Residential Code for One- and Two-

Family Dwellings. Falls Church, VA.

Mike Smith Enterprises Blog. (May 21, 2013). One more time: Moore had plenty of warning.

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Retrieved from http://meteorologicalmusings.blogspot.com/2013/05/one-more-time-moore-

had-plenty-of.html

Moore, Oklahoma. Emergency Operations Plan. Retrieved from

http://www.cityofmoore.com/sites/default/files/main-

site/2012%20Emergency%20Operations%20Plan.pdf.

Romano, A. (May 22, 2013). The Daily Beast. When the sirens wailed. Retrieved from

http://www.thedailybeast.com/newsweek/2013/05/22/moore-oklahoma-again-in-a-tornado-s-

path.html.

Simmons, Kevin M. and Daniel Sutter. (2011). Economic and Societal Impacts of Tornadoes.

American Meteorological Society. Boston, MA.

Sistek, S. (May, 21, 2013). How tornado victims got 36 minutes of precious warning time.

Komonews. Retrieved from http://www.komonews.com/weather/blogs/scott/How-

technology-helped-give-nearly-30-minutes-warning-of-impending-tornado-208363551.html.

Appendix

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 57

APPENDIX. TORNADO EMERGENCY PROCEDURES FOR SURVEYED FACILITIES

Moore Public School District:

The Moore Public Schools provided NIST with the information documented in this section on

the school’s emergency procedures in the event of a tornado. All schools are required to prepare

a tornado plan, including instructions to take cover against an inside wall, away from windows.

Additionally, the school district’s plan states that all schools should coordinate their specific

emergency preparedness plan with the City of Moore’s Emergency Management Department.

All schools are required to have a NOAA weather radio, which should be monitored in the

school by a staff member, e.g., in the school’s main office, which is normally continuously

staffed.

The Moore school’s response or action plan in the event of a tornado involves five steps:

1. Monitor the proximity of the tornado. The individual responsible for this action is the

Building Administrator or Superintendent. The resource needed for this action is a

television or radio.

2. If a tornado watch is issued, the Building Administrator or equivalent designee should

monitor all outdoor activities and curtail activities if the weather conditions warrant.

3. If a tornado warning is issued, the Building Administrator (or equivalent designee) and/or

the Director of Transportation should summon all persons into the buildings. This

involves getting staff and students off of the playgrounds, stadiums, and practice fields,

as well as out of the portable buildings, if the school contains these types of buildings.

The Superintendent’s office is responsible for relaying this information to the schools’

Building Administrators and Directors of Transportation.

4. If tornado sirens are activated or if a tornado is sighted in the vicinity of the school, the

Building Administrator (or equivalent designee) should institute the tornado emergency

plan. According to the Plaza Towers Elementary School’s tornado emergency procedures

(and similar to those at Briarwood Elementary School), the teachers and staff are made

aware of the need to take shelter from a tornado by the initiation of “one long continuous

ringing of the bell.” After this signal, the students and school staff must institute the

“duck and cover” plan, which is outlined below.

a. Teachers and administrators lead students immediately and orderly to the school’s

specific designated shelter areas.

b. Students and others should stay clear of all glassed areas (e.g., windows). This

includes reinforced glass sections near the doors of the schools.

c. Teachers should take with them their class record book to use for roll call after the

tornado has passed.

d. Students, who are located in designated areas, should assume the following

position: “Face the wall, get down on knees, and lean forward, covering face with

hands and arms.” Additionally, the emergency procedures state that since

tornadoes move fairly quickly (i.e., at a high rate of speed), students can crowd

close together for protection since they will not necessarily need to hold this

position for long.

Appendix

58 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado

5. The principal or administrator will then determine when the all-clear signal will be

announced at the school.

Moore schools hold tornado/severe weather drills every semester. Another policy of Moore

Public School District is that during a tornado watch or warning, teachers and administrators will

not dismiss a student to go home unless the student’s parent comes to the school to pick up

him/her. Students not picked up are automatically sheltered in the school where they are located.

Moore Medical Center:

Information on the Moore Medical Center’s tornado emergency procedures described in this

section was provided by the Center’s Manager of Safety.58

In this hospital’s system, called the

Code Black Plan, there are three levels of alert for a weather-related emergency: Code Black

Watch; Code Black Warning; and Code Black Alert.

In the event of a “Code Black Watch,” all health system personnel are to begin preparation for

the possibility of a tornado or a severe weather warning. Under a “Code Black Watch”, hospital

staff must begin preparation activities, as follows:

Check in with supervisor/manager and coordinate actions and responsibilities if

conditions are upgraded to a warning or alert.

Move all unnecessary equipment, carts, etc. from hallways, elevator areas, and exits, and

ensure that no doors are locked or blocked.

Locate all emergency supplies, including flashlights, oxygen cylinders,

wheelchairs/stretchers, etc.

Keep telephone calls to a minimum.

Additionally, the Nursing House Supervisor (or a designee in charge that day) should determine

which patients can be safely relocated and which need to remain in place. This includes

determining a path of travel that will be followed if patients need to be moved.

In the event of a “Code Black Warning,” all health system personnel should do the following:

Check in with the supervisor/manager.

Close all doors, including the fire and smoke doors, windows, blinds, and draperies in

his/her area and surrounding hallways.

Unplug or shut off any non-essential electrical equipment.

Ensure that all cash boxes, cash registers, medicine and narcotic cabinets are locked and

secure.

Keep telephone calls to a minimum.

Stay away from all outside windows/doors.

The third and final level in this “Code Black Plan” is a “Code Black Alert.” In a “Code Black

Alert,” all health system personnel should do the following:

Move bed patients to the hallway against the walls and away from outside windows. If

possible, the head of the bed should be elevated. Also, the patient should be facing away

58

NIST Interview #10 (Manager of Safety, Moore Medical Center).

Appendix

NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado 59

from the window at the end of the hallway.

Transfer or relocate ambulatory patients to "designated protected areas" along with all

visitors. Patients and visitors are instructed to remain there until the "ALL CLEAR" is

sounded.

All personnel not in their work area or on a patient floor should report to the nearest

nursing station and remain there until the "ALL CLEAR" has been announced.

Additionally, under “Code Black Alert,” visitors are advised to either remain with the patients or

take shelter in specific locations within the medical center.

According to the emergency operations plans, a “Code Black” watch, warning, or alert must be

declared by the Safety Officer, Nursing House Supervisor, or Administrator on Call. Decisions

on issuing watches, warnings, or alerts are made by obtaining information on the weather

emergency via multiple sources and means of communications, including weekly webinars

provided by the WCM from the NWS Forecast Office in Norman, 800 MHz radios, NWS radar

imagery obtained via the web or phone, local news radar and spotter/helicopter information

provided via television or radio, and automated weather updates obtained via phone or email.

Once a decision is made, emergency information and instructions are then relayed to health

system personnel and patients via an overhead page to the entire hospital campus.

Before the May 20, 2013 Newcastle-Moore tornado, hospital staff and leadership met monthly to

review plans and preparations for severe weather. On average, “Code Black” alerts were issued

for Moore Medical Center two times each spring.

Appendix

60 NIST SP 1164, Preliminary Reconnaissance Report – Newcastle-Moore Tornado